libcamera: Standardize on 'const auto'

'const auto' and 'auto const' are interchangeable in C++. There are 446
occurrences of the former in the code base, and 67 occurrences of the
latter. Standardize on the winner.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>

src/libcamera/v4l2_videodevice.cpp

@@ -206,7 +206,7 @@ V4L2BufferCache::~V4L2BufferCache()
  */
 bool V4L2BufferCache::isEmpty() const
 {
-	for (auto const &entry : cache_) {
+	for (const auto &entry : cache_) {
 		if (!entry.free_)
 			return false;
 	}