mmc: mmc_spi: Move argument check to the beginning of mmc_spi_sendcmd()

The argument check should happen before any transfer on the SPI lines.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/mmc_spi.c b/drivers/mmc/mmc_spi.c
index 23b9073..a06862a 100644
--- a/drivers/mmc/mmc_spi.c
+++ b/drivers/mmc/mmc_spi.c
@@ -78,6 +78,9 @@
 	int i, rpos = 0, ret = 0;
 	u8 cmdo[7], r;
 
+	if (!resp || !resp_size)
+		return 0;
+
 	debug("%s: cmd%d cmdarg=0x%x resp_type=0x%x "
 	      "resp_size=%d resp_match=%d resp_match_value=0x%x\n",
 	      __func__, cmdidx, cmdarg, resp_type,
@@ -98,9 +101,6 @@
 	if (ret)
 		return ret;
 
-	if (!resp || !resp_size)
-		return 0;
-
 	debug("%s: cmd%d", __func__, cmdidx);
 
 	if (resp_match) {