mm-video: vdec: post fbd_sem after pushing fbd to queue

In certain flush-sleep-pause-resume scenarios,
fbd_thread ends up waiting on a empty semaphore
fbd_sem, after EOS is reached i.e. there
will be no more posts on fbd_sem. This results in the
test app being stuck infinitely on the semaphore.

CRs-fixed: 486616
Change-Id: I6b27bb41a6b7778fccd779dcaafdaeb4ea541206
1 file changed