stress_floppy: Add 'datafiles'

* Modify 'io_floppy'.

* Move '1K_file', 'dd_file' and 'generate.sh' into 'datafiles'.

* Install '1K_file', 'dd_file' and 'generate.sh' to
  'testcases/data/stress_floppy'.

* Some cleanup.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
8 files changed