BQ enables this in the config. Remove here

Marlin/Conditionals_LCD.h

@@ -62,7 +62,6 @@
   #elif ENABLED(BQ_LCD_SMART_CONTROLLER)
 
     #define REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
-    #define LONG_FILENAME_HOST_SUPPORT
 
   #elif ENABLED(miniVIKI) || ENABLED(VIKI2) || ENABLED(ELB_FULL_GRAPHIC_CONTROLLER)