Pass mode to wait_on_atomic_t() action funcs and provide default actions

Make wait_on_atomic_t() pass the TASK_* mode onto its action function as an
extra argument and make it 'unsigned int throughout.

Also, consolidate a bunch of identical action functions into a default
function that can do the appropriate thing for the mode.

Also, change the argument name in the bit_wait*() function declarations to
reflect the fact that it's the mode and not the bit number.

[Peter Z gives this a grudging ACK, but thinks that the whole atomic_t wait
should be done differently, though he's not immediately sure as to how]

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
cc: Ingo Molnar <mingo@kernel.org>

fs/fscache/main.c

@@ -195,12 +195,3 @@ static void __exit fscache_exit(void)
 }
 
 module_exit(fscache_exit);
-
-/*
- * wait_on_atomic_t() sleep function for uninterruptible waiting
- */
-int fscache_wait_atomic_t(atomic_t *p)
-{
-	schedule();
-	return 0;
-}