ec: Fix more mutex related coverity scan issues

This patch solves CID 1257622.

Change-Id: I95680c7de49cd84011d2ad38f02e5fad82e15c90
BUG: 1170254
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/9263
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>