Break after handling the read/write

The loop is there because watchers may have two Watcher for the same
fd, one for read and one for write, but after we're processed the
correct one we don't need to keep looping.

This fixes a crash since it's possible that while in processing
q_dbus_watch_handle we get a watch added/remove this invalidating
the iterator and crashing

Change-Id: Icb61deae272d2f237a4c616fae598404d419af90
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusintegrator.cpp

@@ -1184,6 +1184,7 @@ void QDBusConnectionPrivate::socketRead(int fd)
         if (it->watch && it->read && it->read->isEnabled()) {
             if (!q_dbus_watch_handle(it.value().watch, DBUS_WATCH_READABLE))
                 qDebug("OUT OF MEM");
+            break;
         }
         ++it;
     }
@@ -1198,6 +1199,7 @@ void QDBusConnectionPrivate::socketWrite(int fd)
         if (it->watch && it->write && it->write->isEnabled()) {
             if (!q_dbus_watch_handle(it.value().watch, DBUS_WATCH_WRITABLE))
                 qDebug("OUT OF MEM");
+            break;
         }
         ++it;
     }