Remove unidentified logic inside of __ms_bus_cb() for state change

Remove unidentified logic inside of __ms_bus_cb() for state change

In case of MEDIA_STREAMER_STATE_READY/PAUSED/PLAYING, the pend state
of media streamer handle is set by API. After then, the state of
media stream handle is set in bus message callback with the pend state.

But the removed logic in this commit set these states of the handle
forcedly from the bus message callback. We can't find the situation
that it happens as well as we find it causes a bug of state change
in case of WebRTC execution. Hence, it is now removed.

Coding style and logs are also revised.

[Version] 0.1.87
[Issue Type] Bug fix

Change-Id: I06e89837101b0d9d894643d4323a7e102828e9a7
Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>