pytools: obmcutil: Properly use format string

This changes the format slightly, but not for the worse in my opinion.

Change-Id: Ie9297c22f8c3ceff4fc56ae567dbdbb0f128dd51
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/pytools/obmcutil b/pytools/obmcutil
index 396a394..48b90dd 100644
--- a/pytools/obmcutil
+++ b/pytools/obmcutil
@@ -120,7 +120,7 @@
                 dbus_iface.Set(iface, prop, val)
             else:
                 dbus_prop = dbus_iface.Get(iface, prop)
-                print '{:<20}'.format(prop+": ") + str(dbus_prop)
+                print '{:<20}: {}'.format(prop, str(dbus_prop))
         else:
             dbus_iface = dbus.Interface(dbus_obj, "org.freedesktop.DBus.Properties")
             props = dbus_iface.GetAll(iface)