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>

test/camera/capture.cpp

@@ -63,7 +63,7 @@ protected:
 			return TestFail;
 		}
 
-		allocator_ = FrameBufferAllocator::create(camera_);
+		allocator_ = new FrameBufferAllocator(camera_);
 
 		return TestPass;
 	}

test/camera/statemachine.cpp

@@ -117,7 +117,7 @@ protected:
 			return TestFail;
 
 		/* Use internally allocated buffers. */
-		allocator_ = FrameBufferAllocator::create(camera_);
+		allocator_ = new FrameBufferAllocator(camera_);
 		Stream *stream = *camera_->streams().begin();
 		if (allocator_->allocate(stream) < 0)
 			return TestFail;