[SCSI] qla2xxx: Additional residual-count corrections during UNDERRUN handling.

Add additional tightening of residual-count handling (originally
from commit 6acf8190) where the
driver should discard any lower SCSI-status during
firmware/transport residual-count mismatches.
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/qla2xxx/qla_isr.c

@@ -1060,8 +1060,9 @@ qla2x00_status_entry(scsi_qla_host_t *ha, void *pkt)
 		resid = resid_len;
 		/* Use F/W calculated residual length. */
 		if (IS_FWI2_CAPABLE(ha)) {
-			if (scsi_status & SS_RESIDUAL_UNDER &&
-			    resid != fw_resid_len) {
+			if (!(scsi_status & SS_RESIDUAL_UNDER)) {
+				lscsi_status = 0;
+			} else if (resid != fw_resid_len) {
 				scsi_status &= ~SS_RESIDUAL_UNDER;
 				lscsi_status = 0;
 			}