[PATCH] Missing __user in pointer referenced within copy_from_user

Pointers to user data should be marked with a __user hint.  This one is
missing.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>