v4l2_codec2: zero v4l2_rect field before performing IOCTL.

This CL performs a small bit of cleanup, clearing the v4l2_rect data
before performing an IOCTL.

Bug: 143333813
Test: arc.VideoEncodeAccel.h264_192p_i420_vm
Change-Id: Ie24daa1d37b867a53acf0734c457ba47ad6e2d12

components/V4L2Encoder.cpp

@@ -501,6 +501,7 @@ bool V4L2Encoder::configureInputFormat(media::VideoPixelFormat inputFormat, uint
     media::Rect visibleRectangle(mVisibleSize.width(), mVisibleSize.height());
 
     struct v4l2_rect rect;
+    memset(&rect, 0, sizeof(rect));
     rect.left = visibleRectangle.x();
     rect.top = visibleRectangle.y();
     rect.width = visibleRectangle.width();