Hide the %AMDP2_FE-6-EXCESSCOLL error

The IOU %AMDP2_FE-6-EXCESSCOLL error can be L2 IOU high CPU usage. To completely hide that error a user (thank you, Marius) suggests the following configuration on each L2 device:

logging discriminator EXCESS severity drops 6 msg-body drops EXCESSCOLL
logging buffered 50000
logging console discriminator EXCESS