signals: rename rm_from_queue_full() to flush_sigqueue_mask()

signals: rename rm_from_queue_full() to flush_sigqueue_mask()

"rm_from_queue_full" looks ugly and misleading, especially now that
rm_from_queue() has gone away.  Rename it to flush_sigqueue_mask(), this
matches flush_sigqueue() we already have.

Also remove the obsolete comment which explains the difference with
rm_from_queue() we already killed.

Signed-off-by: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Al Viro <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>