For unused switch ports all MIB values are zero. Displaying ~40 empty
MIB counters is just confusing and makes it hard to read the output of
swconfig dev <dev> show.
Therefore, if all MIB counters for a port are zero, just display
an info that the MIB counters are empty.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
SVN-Revision: 48910
76e1efc042