cifs: clean up sync_mid_result

Make it use a switch statement based on the value of the midStatus. If
the resp_buf is set, then MID_RESPONSE_RECEIVED is too.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index f65cdec..6abd144 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -363,28 +363,29 @@
 {
 	int rc = 0;
 
-	spin_lock(&GlobalMid_Lock);
+	cFYI(1, "%s: cmd=%d mid=%d state=%d", __func__, mid->command,
+		mid->mid, mid->midState);
 
-	if (mid->resp_buf) {
+	spin_lock(&GlobalMid_Lock);
+	switch (mid->midState) {
+	case MID_RESPONSE_RECEIVED:
 		spin_unlock(&GlobalMid_Lock);
 		return rc;
-	}
-
-	cERROR(1, "No response to cmd %d mid %d", mid->command, mid->mid);
-	if (mid->midState == MID_REQUEST_SUBMITTED) {
-		if (server->tcpStatus == CifsExiting)
+	case MID_REQUEST_SUBMITTED:
+		/* socket is going down, reject all calls */
+		if (server->tcpStatus == CifsExiting) {
+			cERROR(1, "%s: canceling mid=%d cmd=0x%x state=%d",
+			       __func__, mid->mid, mid->command, mid->midState);
 			rc = -EHOSTDOWN;
-		else
-			mid->midState = MID_RETRY_NEEDED;
-	}
-
-	if (rc != -EHOSTDOWN) {
-		if (mid->midState == MID_RETRY_NEEDED) {
-			rc = -EAGAIN;
-			cFYI(1, "marking request for retry");
-		} else {
-			rc = -EIO;
+			break;
 		}
+	case MID_RETRY_NEEDED:
+		rc = -EAGAIN;
+		break;
+	default:
+		cERROR(1, "%s: invalid mid state mid=%d state=%d", __func__,
+			mid->mid, mid->midState);
+		rc = -EIO;
 	}
 	spin_unlock(&GlobalMid_Lock);