coding style: join consecutive string fragments

coding style: join consecutive string fragments

The re is no need to split a long string, apart for fitting the
predefined line width.
Join the consecutive string fragments.

Issue identified by checkpatch script from Linux kernel v5.1 using
the command

	find src/ -type f -exec ./tools/scripts/checkpatch.pl \
	-q --types STRING_FRAGMENTS -f {} \;

Change-Id: I8de52d572b0e3d4788c1d4d2b0cf8f94c7f08409
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5625
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>