Cleanup: use "free_data" suffix when the argument isn't freed

Avoid API misuse that caused leaks in T90791 &
2788b0261c.

source/blender/editors/screen/screen_edit.c

@@ -230,7 +230,7 @@ bScreen *screen_add(Main *bmain, const char *name, const rcti *rect)
 void screen_data_copy(bScreen *to, bScreen *from)
 {
   /* free contents of 'to', is from blenkernel screen.c */
-  BKE_screen_free(to);
+  BKE_screen_free_data(to);
 
   to->flag = from->flag;