emacs: fix warning

emacs/init.el

@@ -119,7 +119,8 @@
   :mode (("\\.zsc\\'" . c-mode)
          ("\\.zc\\'"  . c-mode))
   :init
-  (setq c-auto-align-backslashes nil)
+  (setq c-auto-align-backslashes nil
+        c-basic-offset           tab-width)
   (defvaralias 'c-basic-offset 'tab-width))
 
 (use-package fish-mode