libcamera: buffer: Drop private function setRequest()

There is no need to have a private helper function to access a private
data member when a friend statement is needed anyhow. Remove the helper
function to simplify the code and make it clear that a private member of
Buffer is accessed.

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

include/libcamera/buffer.h

@@ -129,8 +129,6 @@ private:
 
 	void cancel();
 
-	void setRequest(Request *request) { request_ = request; }
-
 	unsigned int index_;
 	std::array<int, 3> dmabuf_;
 	BufferMemory *mem_;

src/libcamera/buffer.cpp

@@ -290,7 +290,6 @@ Buffer::Buffer(unsigned int index, const Buffer *metadata)
  *
  * \return The Request the Buffer belongs to, or nullptr if the buffer is
  * either completed or not associated with a request
- * \sa Buffer::setRequest()
  */
 
 /**
@@ -318,10 +317,11 @@ void Buffer::cancel()
 }
 
 /**
- * \fn Buffer::setRequest()
- * \brief Set the request this buffer belongs to
+ * \var Buffer::request_
+ * \brief The request this buffer belongs to
  *
- * The intended callers are Request::addBuffer() and Request::completeBuffer().
+ * This member is intended to be set by Request::addBuffer() and
+ * Request::completeBuffer().
  */
 
 /**

src/libcamera/request.cpp

@@ -139,7 +139,7 @@ int Request::addBuffer(std::unique_ptr<Buffer> buffer)
 		return -EEXIST;
 	}
 
-	buffer->setRequest(this);
+	buffer->request_ = this;
 	pending_.insert(buffer.get());
 	bufferMap_[stream] = buffer.release();
 
@@ -236,7 +236,7 @@ bool Request::completeBuffer(Buffer *buffer)
 	int ret = pending_.erase(buffer);
 	ASSERT(ret == 1);
 
-	buffer->setRequest(nullptr);
+	buffer->request_ = nullptr;
 
 	if (buffer->status() == Buffer::BufferCancelled)
 		cancelled_ = true;