Fixing 'cd' function to use fish's 'cd' function and not the builtin command

plugins/cd/cd.fish

-function cd --description "Change working directory"
-  # Source a .rvmrc file in a directory after changing to it, if it exists.
-  # To disable this feature, set rvm_project_rvmrc=0 in $HOME/.rvmrc
+#
+# Source a .rvmrc file in a directory after changing to it, if it exists.
+# To disable this feature, set rvm_project_rvmrc=0 in $HOME/.rvmrc
+#
+function cd --description "Change directory"
+  redefine_function 'cd' "$__fish_datadir/functions/cd.fish" '
+    function cd --description "Change working directory"
+      old_cd "$argv"
 
-  builtin cd "$argv"
       if test "$rvm_project_rvmrc" != 0
         set -l cwd $PWD
         while true
@@ -23,4 +27,8 @@ function cd --description "Change working directory"
 
         set -e cwd
       end
+    end
+'
+
+  cd "$argv"
 end