scsi: fix typo in setup_read_ext()

This clears the 6th byte of cmd twice rather than setting the 9th byte
to 0. Fix it.

The only other command that sets the 9th byte is the 64-bit read, so
this likely never caused issues in practise.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index cd0b84c..34ac47c 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -90,7 +90,7 @@
 	pccb->cmd[6] = 0;
 	pccb->cmd[7] = (unsigned char)(blocks >> 8) & 0xff;
 	pccb->cmd[8] = (unsigned char)blocks & 0xff;
-	pccb->cmd[6] = 0;
+	pccb->cmd[9] = 0;
 	pccb->cmdlen = 10;
 	pccb->msgout[0] = SCSI_IDENTIFY; /* NOT USED */
 	debug("scsi_setup_read_ext: cmd: %02X %02X startblk %02X%02X%02X%02X blccnt %02X%02X\n",