protocol/client: handle more NULL dereference
protocol/client: handle more NULL dereference

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

BUG: 1745 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1745

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster