staging: r8723au: Fix sparse errors in os_dep/osdep_service.c

Sparse reports

drivers/staging/rtl8723au/os_dep/osdep_service.c:24:20: error: Bad character constant
drivers/staging/rtl8723au/os_dep/osdep_service.c:25:0: error: Bad character constant

The constant in question is never used.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/os_dep/osdep_service.c

@@ -21,8 +21,6 @@
 #include <recv_osdep.h>
 #include <linux/vmalloc.h>
 
-#define RT_TAG	('1178')
-
 /*
 * Translate the OS dependent @param error_code to OS independent RTW_STATUS_CODE23a
 * @return: one of RTW_STATUS_CODE23a