scsi: libsas: Remove redundant assignment to variable res

The variable 'res' is being initialized with a value that is never read and
it is being updated later with a new value. The initialization is redundant
and can be removed.

Link: https://lore.kernel.org/r/20200722154404.959267-1-colin.king@canonical.comReviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Addresses-Coverity: ("Unused value")

drivers/scsi/libsas/sas_expander.c

@@ -427,7 +427,7 @@ int sas_ex_phy_discover(struct domain_device *dev, int single)
 static int sas_expander_discover(struct domain_device *dev)
 {
 	struct expander_device *ex = &dev->ex_dev;
-	int res = -ENOMEM;
+	int res;
 
 	ex->ex_phy = kcalloc(ex->num_phys, sizeof(*ex->ex_phy), GFP_KERNEL);
 	if (!ex->ex_phy)