[PATCH] Add GFP_NOWAIT

Introduce GFP_NOWAIT, as an alias for GFP_ATOMIC & ~__GFP_HIGH.

This also changes XFS, which is the only in-tree user of this idiom that I
could find.  The XFS piece is compile-tested only.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>