msm: camera: isp: check stream state before accessing lock

Issue: When VFE fatal occurs stream state set as inactive,
so all the stream info parameters are zero after that
it's trying access the stream info lock which zero hence
it leads spinlock bad magic.

Resolution: check stream state before accessing stream_info
parameters.

CRs-Fixed: 1048053

Change-Id: I2cee1848c3862d0fa8439c8a9c6bb2a72315e9e0
Signed-off-by: Ramesh V <ramev@codeaurora.org>