msm: Camera buffer overflow fix

find_first_zero bit is considering addr parameter as unsigned
long and we are passing int variable.In the function it access
addr[i], so it tries to access 8 bytes , actual size of
open_idx and stream_id are 4 bytes.we change open_idx and
stream_id to long to fix it.

Change-Id: I510059cc8f495957bd2b5af9973b3495761edd06
Signed-off-by: Manish Poddar <mpoddar@codeaurora.org>