libcamera: Always check return value of MediaDevice::acquire()

In preparation for adding more responsibility to MediaDevice::acquire()
remove unneeded calls to acquire() and release(), and make sure all
needed calls to acquire() are checked and acted on.

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

src/libcamera/pipeline/ipu3/ipu3.cpp

@@ -614,21 +614,19 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator)
 	imgu_dm.add("ipu3-imgu 1 viewfinder");
 	imgu_dm.add("ipu3-imgu 1 3a stat");
 
-	/*
-	 * It is safe to acquire both media devices at this point as
-	 * DeviceEnumerator::search() skips the busy ones for us.
-	 */
 	cio2MediaDev_ = enumerator->search(cio2_dm);
 	if (!cio2MediaDev_)
 		return false;
 
-	cio2MediaDev_->acquire();
+	if (!cio2MediaDev_->acquire())
+		return false;
 
 	imguMediaDev_ = enumerator->search(imgu_dm);
 	if (!imguMediaDev_)
 		return false;
 
-	imguMediaDev_->acquire();
+	if (!imguMediaDev_->acquire())
+		return false;
 
 	/*
 	 * Disable all links that are enabled by default on CIO2, as camera

src/libcamera/pipeline/uvcvideo.cpp

@@ -183,7 +183,8 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
 	if (!media_)
 		return false;
 
-	media_->acquire();
+	if (!media_->acquire())
+		return false;
 
 	std::unique_ptr<UVCCameraData> data = utils::make_unique<UVCCameraData>(this);
 

src/libcamera/pipeline/vimc.cpp

@@ -193,7 +193,8 @@ bool PipelineHandlerVimc::match(DeviceEnumerator *enumerator)
 	if (!media_)
 		return false;
 
-	media_->acquire();
+	if (!media_->acquire())
+		return false;
 
 	std::unique_ptr<VimcCameraData> data = utils::make_unique<VimcCameraData>(this);