lib/win_minmax: fix header comments

Don't use "/**" kernel-doc comment marker for non-kernel-doc
comment.

Correct the filename but omit the path since we know where it is
and it could change (but not likely).

Link: https://lkml.kernel.org/r/20240107220155.29013-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>