drm: Make vblank_disable_allowed bool

vblank_disable_allowed is only ever 0 or 1, so make it a bool.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 2b9b033..06cb8f7 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1151,7 +1151,7 @@
 	 * Once the modeset ioctl *has* been called though, we can safely
 	 * disable them when unused.
 	 */
-	int vblank_disable_allowed;
+	bool vblank_disable_allowed;
 
 	wait_queue_head_t *vbl_queue;   /**< VBLANK wait queue */
 	atomic_t *_vblank_count;        /**< number of VBLANK interrupts (driver must alloc the right number of counters) */