There is no bashism in the scripts, so use /bin/sh, and add /bin/sh
interpreter for systemd's run-ptest.
(From OE-Core rev: 62d455f89fb1d2c22cf987bdbb56a55e6d031ce0)
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>