scripts/qemuimage-testlib: Use wide option to ps calls

scripts/qemuimage-testlib: Use wide option to ps calls

Forcing ps to display unlimited column width allows the qemu IP address to
be discovered during sanity testing when the command line is extremely long.

This seems to fix the sanity testing problem on AB05 which was recently updated
to OpenSUSE 12.2. I'm not sure what about qemu or process listing is different
on that distribution but this simpile fix seems to work and my help on other
distro's as well.

(From OE-Core rev: 4cea35cc4e4ed8e68cd117825b1dd4ef1be768c2)

Signed-off-by: Michael Halstead <michael@yoctoproject.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>