libcamera: framebuffer: Replace vector with span in constructor

The FrameBuffer constructor takes a list of planes as an std::vector.
The caller may stores the planes in a different type of container,
resulting in the needless allocation of a temporary vector. Replace it
with a span.

Suggested-by: Daniel Rákos <daniel.rakos@rastergrid.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -1031,9 +1031,12 @@ int PipelineHandlerRkISP1::allocateBuffers(Camera *camera)
 	auto pushBuffers = [&](const std::vector<std::unique_ptr<FrameBuffer>> &buffers,
 			       std::queue<FrameBuffer *> &queue) {
 		for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
+			Span<const FrameBuffer::Plane> planes = buffer->planes();
+
 			buffer->setCookie(ipaBufferId++);
 			data->ipaBuffers_.emplace_back(buffer->cookie(),
-						       buffer->planes());
+						       std::vector<FrameBuffer::Plane>{ planes.begin(),
+											planes.end() });
 			queue.push(buffer.get());
 		}
 	};