On x86-64, a put_user call using a 64-bit pointer and a constant value that
is > 0xffffffff will produce code that doesn't assemble. This patch fixes
the asm construct to use the Z constraint for 32-bit constants.
Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>