drm: Unify and fix idr error handling

The error handling code w.r.t. idr usage looks inconsistent.

In the case of drm_mode_object_get() and drm_ctxbitmap_next() the error
handling is also incomplete.

Unify the code to follow the same pattern always.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index aa454f8..ae1ccf1 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -122,11 +122,10 @@
 	ret = idr_get_new_above(&drm_minors_idr, NULL,
 				base, &new_id);
 	mutex_unlock(&dev->struct_mutex);
-	if (ret == -EAGAIN) {
+	if (ret == -EAGAIN)
 		goto again;
-	} else if (ret) {
+	else if (ret)
 		return ret;
-	}
 
 	if (new_id >= limit) {
 		idr_remove(&drm_minors_idr, new_id);