Minor code refactoring

In the Topsy case, pre-calculate `mapped_key.raw` for both branches, and only
modify its flags in the unishfted branch. This saves us about a dozen bytes of
PROGMEM.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

src/Kaleidoscope/TopsyTurvy.cpp

@@ -50,10 +50,10 @@ EventHandlerResult TopsyTurvy::onKeyswitchEvent(Key &mapped_key, byte row, byte
   }
 
   is_active_ = keyIsPressed(key_state);
+  mapped_key.raw = mapped_key.raw - ranges::TT_FIRST;
 
   // invert the shift state
   if (!is_shifted_) {
-    mapped_key.raw = mapped_key.raw - ranges::TT_FIRST;
     mapped_key.flags |= SHIFT_HELD;
     return EventHandlerResult::OK;
   }
@@ -62,7 +62,6 @@ EventHandlerResult TopsyTurvy::onKeyswitchEvent(Key &mapped_key, byte row, byte
     hid::releaseKey(Key_LeftShift);
     hid::releaseKey(Key_RightShift);
 
-    mapped_key.raw = mapped_key.raw - ranges::TT_FIRST;
     return EventHandlerResult::OK;
   }