distribute: Propagate -1 op_ret on failed fop
distribute: Propagate -1 op_ret on failed fop

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

BUG: 1717 (dht_attr_cbk does not propagate op_ret on failed fop causing nfs crash)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1717

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster