st_smi: Read status until timeout happens

SMI driver read status fails because the control register could not be
overwritten. Instead, the read status should be tried until timeout.

Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
Signed-off-by: Amit Virdi <amit.virdi@st.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/mtd/st_smi.c b/drivers/mtd/st_smi.c
index 2c6d59d..088c7c7 100644
--- a/drivers/mtd/st_smi.c
+++ b/drivers/mtd/st_smi.c
@@ -187,7 +187,7 @@
 	do {
 		sr = smi_read_sr(bank);
 		if (sr < 0)
-			break;
+			continue;	/* try until timeout */
 		else if (!(sr & WIP_BIT))
 			return 0;