tst-sendfile: indent using spaces

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
tst-sendfile: add printouts on failures

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
tst-sendfile: fail the test when accept() fails

Otherwise the test could pass even though we didn't check anything.

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
tst-sendfile: fix use of uninitialized variable.

'client_len' was passed to accept() uninitialized which resulted in
erratic EINVAL failures.

Fix by removing it altogether, we're not interested in peer's address.

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>