staging: r8188eu: mark is_basicrate as bool

Mark is_basicrate as bool as it returns true/false.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vihas Makwana <makvihas@gmail.com>
Link: https://lore.kernel.org/r/20220302204737.49056-11-makvihas@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_wlan_util.c

@@ -167,7 +167,7 @@ static unsigned char ratetbl_val_2wifirate(unsigned char rate)
 	return val;
 }
 
-static int is_basicrate(struct adapter *padapter, unsigned char rate)
+static bool is_basicrate(struct adapter *padapter, unsigned char rate)
 {
 	int i;
 	unsigned char val;