Update code for sound focus

Update code for sound focus

There is no action if read session is failed,
but, sound focus watch callback should be set in that case.
So, add code for it and modify some code for sound focus operation.

[Version] 0.10.72
[Profile] Common
[Issue Type] Bug fix
[Dependency module] N/A
[Dependency commit] N/A
[Test] [M(T) - Boot=(OK), sdb=(OK), Home=(OK), Touch=(OK), Version=tizen-mobile_20160830.2]

Change-Id: Ib1953fcec84b332e12b8b814fb0d4afbff5cd88f
Signed-off-by: Jeongmo Yang <jm80.yang@samsung.com>