Minor sed-related cleanup

Signed-off-by: Mel Gorman <mgorman@suse.de>
arraysmash: Test case that just iterates a large array for reclaim disruption

Signed-off-by: Mel Gorman <mgorman@suse.de>
Add mappings for btrfsprogs and xz for Debian

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>