Otherwise systemd uses AC_PROG_PATH and finds it in the sysroot or host
system, which won't work on the target.
[YOCTO #7408]
(From OE-Core rev: 294adc0907a359d9c0ad260823188145aab294ad)
Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>