drm: make drm_core_check_feature() bool that it is

Bool is the more appropriate return type here, use it.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180327204722.31246-3-jani.nikula@intel.com

include/drm/drmP.h

@@ -115,9 +115,9 @@ static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
 #define DRM_SWITCH_POWER_CHANGING 2
 #define DRM_SWITCH_POWER_DYNAMIC_OFF 3
 
-static inline int drm_core_check_feature(struct drm_device *dev, int feature)
+static inline bool drm_core_check_feature(struct drm_device *dev, int feature)
 {
-	return ((dev->driver->driver_features & feature) ? 1 : 0);
+	return dev->driver->driver_features & feature;
 }
 
 /* returns true if currently okay to sleep */