Fix prettier-js-mode-maybe to check for 0 exit code

instead of checking for empty string

.emacs.d/init.el

@@ -984,10 +984,7 @@
   :init
   (defun prettier-js-mode-maybe ()
     (interactive)
-    (when (not (string=
-                 ""
-                 (shell-command-to-string
-                  (concat "prettier --find-config-path " (buffer-file-name)))))
+    (when (not (call-process "prettier" nil nil nil "--find-config-path" (buffer-file-name)))
       (prettier-js-mode t))))
 
 (use-package show-marks