nbd: Pass return value from nbd_handle_list()

While it does not make a difference in practice, nbd_receive_options()
generally returns -errno, so it should do that here as well; and the
easiest way to achieve this is by passing on the value returned by
nbd_handle_list().
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-Id: <1424887718-10800-7-git-send-email-mreitz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

nbd.c

@@ -351,7 +351,7 @@ fail:
 static int nbd_receive_options(NBDClient *client)
 {
     while (1) {
-        int csock = client->sock;
+        int csock = client->sock, ret;
         uint32_t tmp, length;
         uint64_t magic;
 
@@ -398,8 +398,9 @@ static int nbd_receive_options(NBDClient *client)
         TRACE("Checking option");
         switch (be32_to_cpu(tmp)) {
         case NBD_OPT_LIST:
-            if (nbd_handle_list(client, length) < 0) {
-                return 1;
+            ret = nbd_handle_list(client, length);
+            if (ret < 0) {
+                return ret;
             }
             break;