LU-1049 script: lc_net doesn't parse output correctly

LU-1049 script: lc_net doesn't parse output correctly

Port the second fix from bz=23234
The output of ping contains two ip addresses. The regex
matching picks up both addresses. The fix is to add
-m 1 to stop at the first match
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Change-Id: Ie145e710844d80587bf6826822c8db941a4a3bae
Reviewed-on: http://review.whamcloud.com/2057
Reviewed-by: Cliff White <cliffw@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Yu Jian <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>