qemuimage-testlib-pythonhelper: Make the process detection more strict

qemuimage-testlib-pythonhelper: Make the process detection more strict

Old versions of ldd (2.11) as run on some of the autobuilders end up running
commands like "LD_xxxx qemu-system-xxx" which this process detection code
would pick up and result in the wrong PID for qemu.

This changes the code to check for "192.168" in the command so we know
we're getting the correct one. This is less than ideal however we're
running out of options and resolves false negatives we see on the
autobuilder.

(From OE-Core rev: 7b43151bb073f1f6f1fa5a31447b742127060909)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>