stagefright: fix MediaCodecSource.pause() behavior

Don't signal EOS when the source is simply paused.

Bug: 27290834
Change-Id: Id8f0697a3761ae96bfa617fceb1c54558ab82090
diff --git a/media/libstagefright/MediaCodecSource.cpp b/media/libstagefright/MediaCodecSource.cpp
index bdfddc7..5f9a1c0 100644
--- a/media/libstagefright/MediaCodecSource.cpp
+++ b/media/libstagefright/MediaCodecSource.cpp
@@ -286,6 +286,7 @@
                 }
                 if (queue->mPulling && err == OK) {
                     msg->post(); // if simply paused, keep pulling source
+                    break;
                 } else if (err == ERROR_END_OF_STREAM) {
                     ALOGV("stream ended, mbuf %p", mbuf);
                 } else if (err != OK) {