LU-1279 utils: Silence modprobe ptlrpc output in mount.lustre

LU-1279 utils: Silence modprobe ptlrpc output in mount.lustre

Patch d8d9b78a5c08eb1d938ab9e3bdaf7f756bfbb5ec introduced
this modprobe, but order of redirects was reversed which results
in printing spurios messages like "FATAL: Module ptlrpc not found."
when mountig lustre from local build dir.

Change-Id: I688d073ad3b0565f73c29a50c2b81383adfd7a48
Signed-off-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/4449
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>