Reduce string storage, use masking 'seen'

Marlin/src/gcode/feature/powerloss/M413.cpp

@@ -47,7 +47,7 @@ void GcodeSuite::M413() {
   }
 
   #if ENABLED(DEBUG_POWER_LOSS_RECOVERY)
-    if (parser.seen('R') || parser.seen('L')) recovery.load();
+    if (parser.seen("RL")) recovery.load();
     if (parser.seen('W')) recovery.save(true);
     if (parser.seen('P')) recovery.purge();
     if (parser.seen('E')) serialprintPGM(recovery.exists() ? PSTR("PLR Exists\n") : PSTR("No PLR\n"));