bpf, tests: set rlimit also for test_align, so it doesn't fail

When running all the tests, through 'make run_tests', I had
test_align failing due to insufficient rlimit. Set it the same
way as all other test cases from BPF selftests do, so that
test case properly loads everything.

  [...]
  Summary: 7 PASSED, 1 FAILED
  selftests: test_progs [PASS]
  /home/foo/net-next/tools/testing/selftests/bpf
  Test   0: mov ... Failed to load program.
  FAIL
  Test   1: shift ... Failed to load program.
  FAIL
  Test   2: addsub ... Failed to load program.
  FAIL
  Test   3: mul ... Failed to load program.
  FAIL
  Test   4: unknown shift ... Failed to load program.
  FAIL
  Test   5: unknown mul ... Failed to load program.
  FAIL
  Test   6: packet const offset ... Failed to load program.
  FAIL
  Test   7: packet variable offset ... Failed to load program.
  FAIL
  Results: 0 pass 8 fail
  selftests: test_align [PASS]
  [...]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>