Don't add an empty string suffix to the full category name
Don't add an empty string suffix to the full category name

The default value for categories and sub-categories changed from
None to "". Because of that change we ended up having "kv-" and "2i-"
names.

This patch fixes the condition for including sub-category name in
full name.

Change-Id: Ia013a76a706d3e6e32f36fa95f000c2305d847a8
Reviewed-on: http://review.couchbase.org/70103
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Pavel Paulau <dd88eded64e90046a680e3a6c0828ceb8fe8a0e7@gmail.com>

couchbase/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner