protocol/server: set trans in frame->root
protocol/server: set trans in frame->root

Signed-off-by: Vijay Bellur <vijay@gluster.com>
Signed-off-by: Vijay Bellur <vijay@dev.gluster.com>

BUG: 1477 (server crash at afr_unlock_common_cbk)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1477

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster