libcamera: V4L2BufferCache: Check for hot hit first

Check for a hot cache hit before updating which buffer is best to evict
in case no hot hit is found. This doesn't change the behaviour, but
follows a more logical flow.

Suggested-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/v4l2_videodevice.cpp

@@ -212,15 +212,15 @@ int V4L2BufferCache::get(const FrameBuffer &buffer)
 		if (!entry.free)
 			continue;
 
-		if (use < 0)
-			use = index;
-
 		/* Try to find a cache hit by comparing the planes. */
 		if (entry == buffer) {
 			hit = true;
 			use = index;
 			break;
 		}
+
+		if (use < 0)
+			use = index;
 	}
 
 	if (!hit)