Create PID_FOLDER if it doesn't exist

In fact the folder was already created if the app is running as
a different user, but not if running as the current user, so it
was just a question of moving one line out of an if block.

Fixes gh-5986

spring-boot-tools/spring-boot-loader-tools/src/main/resources/org/springframework/boot/loader/tools/launch.script

@@ -140,8 +140,8 @@ start() {
 do_start() {
   working_dir=$(dirname "$jarfile")
   pushd "$working_dir" > /dev/null
-  if [[ -n "$run_user" ]]; then
   mkdir "$PID_FOLDER" &> /dev/null
+  if [[ -n "$run_user" ]]; then
     checkPermissions || return $?
     chown "$run_user" "$PID_FOLDER"
     chown "$run_user" "$pid_file"