LU-6401 headers: move seq_range.h to correct directory

LU-6401 headers: move seq_range.h to correct directory

in change http://review.whamcloud.com/#/c/16339/ seq_range.h
was put in the wrong directory, and was requested to move it
up a level.

Signed-off-by: Ben Evans <bevans@cray.com>
Change-Id: I461273c4d216714eddc7d4d5c7cdb8ac9f8c8678
Reviewed-on: http://review.whamcloud.com/18863
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>