libcamera: Replace toString with operator<<() for format classes

Now that format classes implement the stream formatting operator<<(),
use it instead of the toString() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/android/jpeg/encoder_libjpeg.cpp

@@ -59,7 +59,7 @@ const struct JPEGPixelFormatInfo &findPixelInfo(const PixelFormat &format)
 	const auto iter = pixelInfo.find(format);
 	if (iter == pixelInfo.end()) {
 		LOG(JPEG, Error) << "Unsupported pixel format for JPEG encoder: "
-				 << format.toString();
+				 << format;
 		return invalidPixelFormat;
 	}
 

src/android/jpeg/thumbnailer.cpp

@@ -30,7 +30,7 @@ void Thumbnailer::configure(const Size &sourceSize, PixelFormat pixelFormat)
 	if (pixelFormat_ != formats::NV12) {
 		LOG(Thumbnailer, Error)
 			<< "Failed to configure: Pixel Format "
-			<< pixelFormat_.toString() << " unsupported.";
+			<< pixelFormat_ << " unsupported.";
 		return;
 	}