syscalls/dup07: Fixes.

The testcases had several problems:

* Wasn't using tst_tmpdir() and created files in CWD

* The main loop contained tst_exit() and because of that
  options as -i and -I weren't working at all

* The fail flag was set only once at the start and not
  reset along the way, so after one failure the rest
  of the tests would be marked as failed

* etc.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
syscalls/dup06: Fixes.

The testcases had several problems:

* Wasn't using tst_tmpdir() and created files in CWD

* The test wasn't closing the filedescriptors and so
  the test has failed on second and any other run (-i or -I)

* The fail flag was set only once at the start and not
  reset along the way, so after one failure the rest
  of the tests would be marked as failed

* etc.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>