tracing: Don't dereference trace_event_file in deferred trigger free

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/trace/trace.h",
                        "kernel/trace/trace_events_trigger.c"
                    ],
                    "versions": [
                        {
                            "version": "e091351b38818ef620d27f44f4bfd625f13afbff",
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                            "status": "affected",
                            "versionType": "git"
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                        {
                            "version": "159fdc3e01dca5fdbc412fcd8b239895733a270d",
                            "status": "affected",
                            "versionType": "git"
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                        {
                            "version": "7.1.6",
                            "lessThan": "7.2",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                }

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/trace/trace.h",
                        "kernel/trace/trace_events_trigger.c"
                    ],
                    "versions": [
                        {
                            "version": "7.2",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.2",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.7",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }