[test_ipinip] Strip ip prefix

[lolyu]

Description of PR

Strip the ip prefix in the ip address passed to simple_ip_packet

Signed-off-by: Longxiang Lyu [email protected]

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Approach

What is the motivation for this PR?

Strip the ip prefix in the ip address passed to simple_ip_packet

How did you do it?

Strip the prefix.

How did you verify/test it?

dualtor/test_ipinip.py::test_decap_active_tor PASSED                                                                                                                                           [ 50%]
dualtor/test_ipinip.py::test_decap_standby_tor FAILED                                                                                                                                          [100%]

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation