bb-matrix-plot.sh: Show underscores correctly in labels
Underscores previously caused the next character in the label to be
printed using subscript due to the enhanced string support in gnuplot.
(From OE-Core rev: 282b48f90f77e0766993018d22fe03dd303febdc)
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Peter Kjellerstedt