s390/cio: remove weird assignment during argument evaluation

Get rid of a useless assignment during argument evaluation.

No functional change.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index 5156264..fc5fb51 100644
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -46,7 +46,7 @@
 		goto out;
 	}
 	req->retries	= req->maxretries;
-	req->mask	= lpm_adjust(req->mask >>= 1, req->lpm);
+	req->mask	= lpm_adjust(req->mask >> 1, req->lpm);
 out:
 	return req->mask;
 }