Fix (unreported): Snap not enabled if Ctrl is pressed before operation

Regression introduced by 88e2542398.

The transform operator has a special way of detecting when the snap
modifier is pressed before the modal.

source/blender/editors/transform/transform_snap.cc

@@ -861,7 +861,7 @@ void initSnapping(TransInfo *t, wmOperator *op)
   }
   /* use scene defaults only when transform is modal */
   else if (t->flag & T_MODAL) {
-    if (transformModeUseSnap(t) && (t->tsnap.flag & SCE_SNAP)) {
+    if (t->tsnap.flag & SCE_SNAP) {
       t->modifiers |= MOD_SNAP;
     }
 
@@ -881,6 +881,8 @@ void initSnapping(TransInfo *t, wmOperator *op)
 
   t->tsnap.source_operation = snap_source;
 
+  transform_snap_flag_from_modifiers_set(t);
+
   initSnappingMode(t);
 }