portmapper: minor fixes
portmapper: minor fixes

* in bind, initialize the array index to port
* in search, check if brickname is NULL

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 1363 (crash is pmap_registry_search())
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1363

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster