msm:camera: Fix overflow issue in ioctl_hw_cmds function

    'len' is of type signed int 32bit,but the assigned value
    may exceed maximum unsigned int32 range.Add overflow check
    and graceful exit if 'm'exceeds UINT32_MAX value.

Change-Id: I38f0d10a0cb44d08d0054f91044fc891c246ebd1
CRs-Fixed: 493314
Signed-off-by: Monika Alekhya <malekh@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>