LU-3319 procfs: move top level proc handling over to seq_file

LU-3319 procfs: move top level proc handling over to seq_file

In the proc tree lustre creates the top level is handled in
the linux module code. For 3.10+ kernel support we adapt
this proc handling to using seq_files.

Signed-off-by: James Simmons <uja.ornl@gmail.com>
Change-Id: I19f2b5d14cdbd97f2591ec8f1eaf174c8c6d4553
Reviewed-on: http://review.whamcloud.com/7294
Tested-by: Jenkins
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>