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: I0ed4bc6b62f26c5e891c1181a6871ee6e4f4f5fd
BUG: 1063190
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/6944
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>