staging: rtl8188eu: remove unused _HAL_INTF_C_ define

This define can be removed.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210725155902.32433-9-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/hal/hal_intf.c

@@ -5,7 +5,6 @@
  *
  ******************************************************************************/
 
-#define _HAL_INTF_C_
 #include <hal_intf.h>
 
 uint rtw_hal_init(struct adapter *adapt)