camera: fix `-Wsign-compare` compiler warnings

Test: add `USE_CAMERA_V4L2_HAL := true` to
      hardware/libhardware/modules/camera/3_4/Android.mk and build
      mmm hardware/libhardware/modules/camera/3_4
Change-Id: I47ee9e39c3bfee7927f4e57dfec459714c959e14
Signed-off-by: Sergii Piatakov <sergii.piatakov@globallogic.com>
2 files changed