vmwgfx: return -EFAULT if copy_to_user fails

copy_to_user() returns the number of bytes remaining to be copied, but
we want to return a negative error code.  This gets copied to user
space.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 file changed