Yi Sun authored Jul 26, 2012 and Daniel Vetter committed Jul 26, 2012

With the option '-r', the testdisplay could paint a 2-D bar code(QR
bar code) on the screen. The word "pass" is hiden in the bar code
image.  Further more, with this option, testdisplay will wait until a
system signal 'SIGUSR1' coming after each mode setting. This function
is for another program to control testdisplay.

danvet: Fix up the missing static.

Signed-off-by: Yi Sun <yi.sun@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>