mmc: use the generic error number

Use the generic error number instead of specific error number.
If use the generic error number, it can debug more easier.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/drivers/mmc/s3c_sdi.c b/drivers/mmc/s3c_sdi.c
index 02d1138..1b8358a 100644
--- a/drivers/mmc/s3c_sdi.c
+++ b/drivers/mmc/s3c_sdi.c
@@ -133,7 +133,7 @@
 
 	if (!timeout) {
 		puts("S3C SDI: Command timed out!\n");
-		ret = TIMEOUT;
+		ret = -ETIMEDOUT;
 		goto error;
 	}
 
@@ -196,7 +196,7 @@
 
 	if (!timeout) {
 		puts("S3C SDI: Command timed out!\n");
-		ret = TIMEOUT;
+		ret = -ETIMEDOUT;
 		goto error;
 	}