Regression tests portability: basic/ec/self-heal.t

When checking for bricks availability, use ls -l produces a more reliable
result than just ls.

BUG: 1129939
Change-Id: Ided548a8f4154714d2c33ec538d0623d7c328952
Signed-off-by: Emmanuel Dreyfus <manu@netbsd.org>
Reviewed-on: http://review.gluster.org/9133
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>