Fix minor spelling mistakes in tests/* Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

TESTS: global_talloc_context push/pop remove Push/pop global_talloc_context into check_leaks is redudant. It is done in leak_check_setup() and leak_check_teardown() functions in src/tests/check_leaks. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

TESTS: Check return value of check_leaks_pop Reviewed-by: Petr Cech <pcech@redhat.com>

TESTS: Initialize leak check If leak_check_setup is not called then global_talloc_context was not initialized and check_leaks_pop(global_talloc_context) will fail. Reviewed-by: Petr Cech <pcech@redhat.com>

tests: convert all unit tests to cmocka 1.0 or later All tests now use the cmocka-1.0-compatible API. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

KRB5: Do not switch_creds() if already the specified user The code didn't have to handle this case previously as sssd_be was always running as root and switching to the ccache as the user logging in. Also handle NULL creds on restore_creds() in case there was no switch. One less if-condition and fewer indentation levels. Related: https://fedorahosted.org/sssd/ticket/2370 Reviewed-by: Sumit Bose <sbose@redhat.com> Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

TESTS: Add a test to change user IDs Adds a unit test using the nss_wrapper and uid_wrapper libraries that exercises the ability to become another user. Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>