Return error if no xcode files where found

plugins/xcode/xcode.plugin.zsh

@@ -2,8 +2,10 @@
 function xc {
   local xcode_proj
   xcode_proj=(*.{xcworkspace,xcodeproj}(N))
+
   if [[ ${#xcode_proj} -eq 0 ]]; then
     echo "No xcworkspace/xcodeproj file found in the current directory."
+    return 1
   else
     echo "Found ${xcode_proj[1]}"
     open "${xcode_proj[1]}"