mm-video: vdec: avoid set metadata after free buffer

In some use cases client frees output buffers before it gets
all FBD's, in this process component clears output buffer
structures it has for current session. Code dependent on
these structures results in crash if it executes after free
buffer. This change checks for such condition and avoids
the same.

CRs-fixed: 614669
Change-Id: Ia2b76425ebc49721beae2f02f5677d18dbff90a2
1 file changed