refactor: unify command declaration across codebase

plugins/ps/subcommands/scale

@@ -6,9 +6,11 @@ source "$PLUGIN_AVAILABLE_PATH/ps/functions"
 
 cmd-ps-scale() {
   declare desc="sets app scaling config via command line"
-  local cmd="ps:scale"
-  [[ -z $2 ]] && dokku_log_fail "Please specify an app to run the command on"
-  shift 1
+  declare cmd="ps:scale"
+  [[ "$1" == "$cmd" ]] && shift 1
+  declare APP="$1"
+
+  [[ -z "$APP" ]] && dokku_log_fail "Please specify an app to run the command on"
   ps_scale "$@"
 }