Revert "glusterd: Fix spurious wakeups in glusterd syncops"

This reverts commit efa154bb0a4cac34d5a9610ec25d38eebe495f22.

-- Following is Avati's analysis (edited) from gerrit --
The claim of the patch (being reverted) is that it in some cases cbkfn
is missed.  This is wrong analysis. cbk_fn is _always_ called. The patch
treats ret > 0 as a "missed cbk". ret > 0 only means socket submission
was not complete, and is queued to submit asynchronously when POLLOUT is
raised.  This is sufficient to guarantee that cbkfn is going to be
called (either the socket errors or submission succeeds and reply
eventually arrives).

This commit also removes spurious barrier_wake(s).

call backs are guaranteed to be called even if the transport is
disconnected. This means, a 'wake' would be called if rpc_clnt_submit is
called.  Also, we count both successful and failed operations in a
particular batch of operations for the synctask_barrier_wait.  So,
calling synctask_barrier_wake on failure of rpc_clnt_submit (say, due to
network failure) would result in a spurious wake.

Change-Id: I7d508c2a54b74a65b82f097742206bc777afc53a
BUG: 948686
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/4922
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>