plymouth/module-setup.sh:installkernel() fix return code

modules.d/50plymouth/module-setup.sh

@@ -45,9 +45,8 @@ installkernel() {
         # Use two parallel streams to filter alternating modules.
         set +x
         eval "( ( rotor ) ${_side2}>&1 | nmf1 ) ${_merge}>&1"
-        _ret=$?
         [[ $debug ]] && set -x
-        return $_ret
+        return 0
     }
 
     for _modname in $(find_kernel_modules_by_path drivers/gpu/drm \