Nozzle.cpp: replace incorrect M_2_PI (2/pi) with 2.0 * M_PI

Marlin/nozzle.cpp

@@ -123,8 +123,8 @@
     for (uint8_t s = 0; s < strokes; s++)
       for (uint8_t i = 0; i < NOZZLE_CLEAN_CIRCLE_FN; i++)
         do_blocking_move_to_xy(
-          middle.x + sin((M_2_PI / NOZZLE_CLEAN_CIRCLE_FN) * i) * radius,
-          middle.y + cos((M_2_PI / NOZZLE_CLEAN_CIRCLE_FN) * i) * radius
+          middle.x + sin((2.0 * M_PI / NOZZLE_CLEAN_CIRCLE_FN) * i) * radius,
+          middle.y + cos((2.0 * M_PI / NOZZLE_CLEAN_CIRCLE_FN) * i) * radius
         );
 
     // Let's be safe