Build fix SensorEventQueue.

Change-Id: I3e6ba031d42bd37067591771f378b7185169ab48
diff --git a/libs/gui/SensorEventQueue.cpp b/libs/gui/SensorEventQueue.cpp
index b5b5d68..8b2018f 100644
--- a/libs/gui/SensorEventQueue.cpp
+++ b/libs/gui/SensorEventQueue.cpp
@@ -154,7 +154,7 @@
    ssize_t size = ::send(mSensorChannel->getFd(), &event, sizeof(event), MSG_NOSIGNAL);
    if (size < 0) {
        ALOGE("injectSensorEvent failure %zd %d", size, mSensorChannel->getFd());
-       return size;
+       return INVALID_OPERATION;
    }
    return NO_ERROR;
 }