selftests/bpf: test_sockmap, timing improvements

Currently 10us delay is too low for many tests to succeed. It needs to
be increased. Also, many corked tests are expected to hit rx timeout
irrespective of timeout value.

- This patch sets 1000usec timeout value for corked tests because less
than that causes broken-pipe error in tx thread. Also sets 1 second
timeout for all other tests because less than that results in RX
timeout
- tests with apply=1 and higher number of iterations were taking lot
of time. This patch reduces test run time by reducing iterations.

real    0m12.968s
user    0m0.219s
sys     0m14.337s

Fixes: a18fda1a ("bpf: reduce runtime of test_sockmap tests")
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>