libcamera: framebuffer_allocator: Lift camera restrictions on allocator

The Camera class currently requires the allocator to have no allocated
buffer before the camera is reconfigured, and the allocator to be
destroyed before the camera is released. There's no basis for these
restrictions anymore, remove them.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/qcam/main_window.cpp

@@ -240,7 +240,7 @@ int MainWindow::startCapture()
 
 	adjustSize();
 
-	allocator_ = FrameBufferAllocator::create(camera_);
+	allocator_ = new FrameBufferAllocator(camera_);
 	ret = allocator_->allocate(stream);
 	if (ret < 0) {
 		std::cerr << "Failed to allocate capture buffers" << std::endl;