[PATCH] mm: pfault optimisation

This atomic operation is superfluous: the pte will be added with the
referenced bit set, and the page will be referenced through this mapping after
the page fault handler returns anyway.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>