cluster/afr: Remove eager-lock stub on finodelk failure

Problem:
For write fops afr's transaction eager-lock init adds transactions
that can share eager-lock to fdctx list. But if eager-lock finodelk
fop fails the stub remains in the list. This could later lead to
corruption of the list and lead to infinite loop on the list
leading to a mount hang.

Fix:
Remove the stub when finodelk fails.

Change-Id: Ic9d1368907c32edb4ea2e6db623e869e4f50180d
BUG: 1063190
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/7748
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Niels de Vos <ndevos@redhat.com>