sched/wait: correct kernel-doc descriptions

sched/wait: correct kernel-doc descriptions

Use the correct function name and function parameter name to avoid
these kernel-doc warnings:

Warning: include/linux/wait_bit.h:424 expecting prototype for
 wait_var_event_killable(). Prototype was for
 wait_var_event_interruptible() instead
Warning: include/linux/wait_bit.h:508 function parameter 'lock' not
 described in 'wait_var_event_mutex'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260302005237.3473095-1-rdunlap@infradead.org