wrap_check_security_groups_policy is already defined

Removes the local method 'wrap_check_security_groups_policy' to
the module neutron_driver.py - This method is already defined
in compute_api.

Change-Id: I008326f7b77515a0fc878befe45fe705420835ad
Closes-Bug: #1314548
Merge "wrap_check_security_groups_policy is already defined"