drm: add proper return value for drm_mode_crtc_set_gamma_size

drm_mode_crtc_set_gamma_size returns boolean true for success
and false for failure. This is not very kernel conform, so
change it to return 0 for success and a propert error code
otherwise. Noone checks the return value, so no users have to
be fixed.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_crtc.c

@@ -3024,7 +3024,7 @@ void drm_mode_connector_detach_encoder(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_mode_connector_detach_encoder);
 
-bool drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
+int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
 				  int gamma_size)
 {
 	crtc->gamma_size = gamma_size;
@@ -3032,10 +3032,10 @@ bool drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
 	crtc->gamma_store = kzalloc(gamma_size * sizeof(uint16_t) * 3, GFP_KERNEL);
 	if (!crtc->gamma_store) {
 		crtc->gamma_size = 0;
-		return false;
+		return -ENOMEM;
 	}
 
-	return true;
+	return 0;
 }
 EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size);
 

include/drm/drm_crtc.h

@@ -919,7 +919,7 @@ extern int drm_mode_connector_attach_encoder(struct drm_connector *connector,
 					     struct drm_encoder *encoder);
 extern void drm_mode_connector_detach_encoder(struct drm_connector *connector,
 					   struct drm_encoder *encoder);
-extern bool drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
+extern int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
 					 int gamma_size);
 extern struct drm_mode_object *drm_mode_object_find(struct drm_device *dev,
 		uint32_t id, uint32_t type);