gstreamer: Move variable to loop scope

The GstBuffer variable in GstLibcameraSrcState::requestCompleted() is
only used within the loop scope. Make it a local loop variable.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

src/gstreamer/gstlibcamerasrc.cpp

@@ -165,10 +165,9 @@ GstLibcameraSrcState::requestCompleted(Request *request)
 		return;
 	}
 
-	GstBuffer *buffer;
 	for (GstPad *srcpad : srcpads_) {
 		Stream *stream = gst_libcamera_pad_get_stream(srcpad);
-		buffer = wrap->detachBuffer(stream);
+		GstBuffer *buffer = wrap->detachBuffer(stream);
 
 		FrameBuffer *fb = gst_libcamera_buffer_get_frame_buffer(buffer);