ec: Avoid self-heal on directories on (f)stat calls

To avoid inconsistent directory listings, a full self-heal
cannot happen on a directory until all its contents have
been healed. This is controlled by a manual command using
getfattr recursively and in post-order.

While navigating the directories, sometimes an (f)stat fop
can be sent. This fop caused a full self-heal of the directory.

This patch makes that (f)stat only initiates a partial self-heal.

This is a backport of http://review.gluster.org/9117/

Change-Id: I0a92bda8f4f9e43c1acbceab2d7926944a8a4d9a
BUG: 1159498
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/9118
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>