Fix heap buffer overflow in a pixel format conversion function

Summary:
Fixes a loop control logic in `FrameConverter::convertTwoRows_1PlaneMosaicPacked10Bit_To_1PlaneUnpacked3Channels8BitAdvanced()`

Setting loop limit to `width - 5u` when `width` is `4u` resulted in loop limit being set to unsigned integer's maximum value due to unsigned integer arithmetic.  This caused the loop to iterate and read/write past buffer boundaries.

Reviewed By: ASchneiderMeta

Differential Revision: D59763520

fbshipit-source-id: 1350c3651c48932bee5f7d6cbfe4a3a3f94406e6

impl/ocean/cv/FrameConverter.cpp

@@ -7166,7 +7166,7 @@ void FrameConverter::convertTwoRows_1PlaneMosaicPacked10Bit_To_1PlaneUnpacked3Ch
 	targetRow0 += 3;
 	targetRow1 += 3;
 
-	for (unsigned int x = 1u; x < width - 5u; x += 4u)
+	for (unsigned int lastSourceElement = 5u; lastSourceElement < width; lastSourceElement += 4u)
 	{
 		// Unpack the next block and then subtract blacklevel and apply white balance
 		unpack5ElementsBayerMosaicPacked10Bit(sourceRowA + 5, sourceBlockA + 4);