Only use debugging variables when debugging

src/multipole.h

@@ -357,10 +357,11 @@ INLINE static void gravity_L2P(const struct gravity_tensors *l,
 
   for (int i = 0; i < gcount; ++i) {
 
+#ifdef SWIFT_DEBUG_CHECKS
     struct gpart *gp = &gparts[i];
 
 // if(gpart_is_active(gp, e)){
-#ifdef SWIFT_DEBUG_CHECKS
+
     gp->mass_interacted += l->mass_interacted;
 #endif
     //}