msm: vidc: Don't kill the session in response handler thread

Kill session will call abort to video hardware and waits for
abort response. So calling kill session from within response
handler thread would always results in wait timeout which in
turn causes session error manipulated to sys error. So don't
kill the session but send error client and client will close
the session.

CRs-Fixed: 2071607
Change-Id: Ic7b57724d57eaf84e90512a732fd9cfb05281b1b
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>