nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()

These records connect through source-stated identifiers. Shared identifiers or dates alone do not establish shared exposure, root cause or applicability.

CVE-2026-89697 · Microsoft / collected KEV context

cve-program · CVE-2026-89697

• https://git.kernel.org/stable/c/3eec9d791968c177a4a8cda9af5c04f79dae09cb
• https://git.kernel.org/stable/c/9229d824b938f4fb0ea7a5dddade51735e6fe6f9
• https://git.kernel.org/stable/c/2150305134889fb2fc25228d35353bd2f6f29500
• https://git.kernel.org/stable/c/d823bf9285cdf4514873b85ab5a888878dd4e8f4
• https://git.kernel.org/stable/c/15ca3b64a69caa6194bed8f98a20ed90a11c11dd
• https://git.kernel.org/stable/c/533964d420d385e11b08dd4c56c66ef5dcccaf08
• https://git.kernel.org/stable/c/c4a409b86a92815181a8e9395c6bf1696ad19175
• https://git.kernel.org/stable/c/4e475be769aa9f7a2c1ce55a2b8592cfccacddcc

No related operational record is retained in the current change model.