build: fix accidental POTFILES.in regression

The original patch for commit 4789fb2e considered renaming a file,
then backed out the name change, but forgot to back out the POTFILES.in
change, resulting in 'make syntax-check' failure.

po/POTFILES.in

@@ -152,5 +152,5 @@ src/xenapi/xenapi_utils.c
 src/xenxs/xen_sxpr.c
 src/xenxs/xen_xm.c
 tools/console.c
-tools/libvirt-guests.init.in
+tools/libvirt-guests.init.sh
 tools/virsh.c