agp: convert drivers/char/agp/frontend.c to use unlocked_ioctl
As of now, agp_compat_ioctl already runs without the BKL. Mutual exclusion
is enforced by agp_fe.agp_mutex in agp_ioctl() and agp_compat_ioctl().
Apply the same locking rationale to the two functions allowing BKL cleanup.
Signed-off-by: Mathieu Segaud <mathieu.segaud@regala.cx> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@linux.ie>