staging: rtl8188eu: remove DBG_88E macro definition

As all callers have now been removed, remove the definition of the
DBG_88E macro itself. It is no longer required and is dead code.
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210615001507.1171-29-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/include/rtw_debug.h

@@ -64,12 +64,6 @@ extern u32 GlobalDebugLevel;
 			pr_info(DRIVER_PREFIX fmt, ##arg);	\
 	} while (0)
 
-#define DBG_88E(...)							\
-	do {								\
-		if (_drv_err_ <= GlobalDebugLevel)			\
-			pr_info(DRIVER_PREFIX __VA_ARGS__);		\
-	} while (0)
-
 #define MSG_88E(...)							\
 	do {								\
 		if (_drv_err_ <= GlobalDebugLevel)			\