serv.py: Fix regression from 972bc43e6d5b

commit 972bc43e6d5b1207b944b3baa8f9805adb35dda7 (serv.py: Fix hang
when spawned dynamically with bitbake) introduced a regression,
because the wrong patch was submitted.  The syntax was incorrect in
the original patch.  The logger iterator must be used with a call to
getLogger().

[YOCTO #5059]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>