This loop was written in a buggy style, causing a NULL driver ptr to be
passed to copyScreen(). copyScreen() only uses that to generate an
identifier string, so this is mostly harmless on systems that accept
NULL for asprintf() "%s" format. (the generated identifiers are off
by one wrt the driver names and the last one contains NULL.
For systems that don't accept NULL for '%s' this would cause a
segmentation fault when this code is used (no xorg.conf, but partial
config in xorg.conf.d for instance).
Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
Reviewed-by: Keith Packard <keithp@keithp.com>