staging: rtl8188eu: remove unused define

_HCI_INTF_C_ was only defined here but not being used anywhere.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/usb_intf.c

@@ -17,7 +17,6 @@
  *
  *
  ******************************************************************************/
-#define _HCI_INTF_C_
 
 #define pr_fmt(fmt) "R8188EU: " fmt
 #include <osdep_service.h>