libcamera: v4l2_videodevice: Rename exportBuffers() to allocateBuffers()

To prepare for the rework of buffer allocation that will differentiate
export and allocation, rename exportBuffers() to allocateBuffers().

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

src/libcamera/include/v4l2_videodevice.h

@@ -189,8 +189,8 @@ public:
 	int setCrop(Rectangle *rect);
 	int setCompose(Rectangle *rect);
 
-	int exportBuffers(unsigned int count,
-			  std::vector<std::unique_ptr<FrameBuffer>> *buffers);
+	int allocateBuffers(unsigned int count,
+			    std::vector<std::unique_ptr<FrameBuffer>> *buffers);
 	int importBuffers(unsigned int count);
 	int releaseBuffers();