storage: fix omitted comma for ceph mon hosts to librados

Add omitted comma for multiple hosts.
Fixes: cdd362e0Signed-off-by: NYi Li <yili@winhong.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/storage/storage_backend_rbd.c

@@ -272,10 +272,10 @@ virStorageBackendRBDOpenRADOSConn(virStorageBackendRBDStatePtr ptr,
             const char *incFormat;
             if (virSocketAddrNumericFamily(source->hosts[i].name) == AF_INET6) {
                 /* IPv6 address must be escaped in brackets on the cmd line */
-                incFormat = "[%s]:%d";
+                incFormat = "[%s]:%d,";
             } else {
                 /* listenAddress is a hostname or IPv4 */
-                incFormat = "%s:%d";
+                incFormat = "%s:%d,";
             }
             virBufferAsprintf(&mon_host, incFormat,
                               source->hosts[i].name,