CVE-2026-72219: lockd: Plug nlm_file leak when nlm_do_fopen() fails

In the Linux kernel, the following vulnerability has been resolved:

lockd: Plug nlmfile leak when nlmdofopen() fails

A client can repeatedly drive nlmdofopen() failures by presenting file handles that the underlying export rejects. After kzallocobj() succeeds in nlmlookupfile(), the freshly allocated nlmfile is not yet inserted into nlmfiles[]. The nlmdofopen() failure path jumps to outunlock, which releases nlmfilemutex and returns without freeing the allocation, so each failure leaks one nlmfile.

Route the failure through outfree so kfree() runs before the function returns.