staging/rts_pstor: remove braces {} in sd.c (downgrade_switch_mode)

fixed below checkpatch warnings.
-WARNING: braces {} are not necessary for single statement blocks
Signed-off-by: Toshiaki Yamane <yamanetoshi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rts_pstor/sd.c

@@ -1160,13 +1160,12 @@ static int sd_check_switch_mode(struct rtsx_chip *chip, u8 mode,
 static u8 downgrade_switch_mode(u8 func_group, u8 func_to_switch)
 {
 	if (func_group == SD_FUNC_GROUP_1) {
-		if (func_to_switch > HS_SUPPORT) {
+		if (func_to_switch > HS_SUPPORT)
 			func_to_switch--;
-		}
+
 	} else if (func_group == SD_FUNC_GROUP_4) {
-		if (func_to_switch > CURRENT_LIMIT_200) {
+		if (func_to_switch > CURRENT_LIMIT_200)
 			func_to_switch--;
-		}
 	}
 
 	return func_to_switch;