ALSA: scarlett2: Use a private URB for the notification endpoint

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "sound/usb/mixer.c",
                        "sound/usb/mixer.h",
                        "sound/usb/mixer_scarlett2.c"
                    ],
                    "versions": [
                        {
                            "version": "1b65088958cadab04d5d34a8615e2466b1b48ecb",
                            "lessThan": "013448eb7b0d0b91d6168685dab10e9b41baa825",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1b65088958cadab04d5d34a8615e2466b1b48ecb",
                            "lessThan": "4305e4b52acc0ca67dcfdf8f73dd943dab508ae8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1b65088958cadab04d5d34a8615e2466b1b48ecb",
                            "lessThan": "04df0232a6976845cd9c9e83b6c26215759be667",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1b65088958cadab04d5d34a8615e2466b1b48ecb",
                            "lessThan": "ecd2f83a4ddc078901e7104144cb6c5e5db3b7cf",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1b65088958cadab04d5d34a8615e2466b1b48ecb",
                            "lessThan": "cd17d6ff7b7d2b1dd9bcc80ae7b4a83773f918c6",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "sound/usb/mixer.c",
                        "sound/usb/mixer.h",
                        "sound/usb/mixer_scarlett2.c"
                    ],
                    "versions": [
                        {
                            "version": "6.10",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.10",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.106",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.47",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.11",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.1",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }