seeker: Use unsigned long instead of blksize_t

Signed-off-by: Mel Gorman <mgorman@suse.de>
seeker: ioctl expects int or weirdness happens

Signed-off-by: Mel Gorman <mgorman@suse.de>
run-mmtests: add support for more configs

Accept multipe config files. This can be used to override values from
the base config (eg. set filesystem type or mount options).

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>