CHROMIUM: sigrok-cli: fix off by one

Avoid memory corruption by an invalid write when adding the NULL terminator
element at the end of the channels list.

Valgrind seems to agree it's necessary.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BUG=none
TEST=run on Valgrind

Change-Id: Ie43e80600b23cbec4d8cd12e3ae5a5405bbef9a4
1 file changed