libdrm: oops fix get cap return value.
diff --git a/xf86drm.c b/xf86drm.c
index bc7a97f..a183eee 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -820,7 +820,7 @@
 		return ret;
 
 	*value = cap.value;
-	return cap.value;
+	return 0;
 }
 
 /**