smb/client: introduce KUnit test to check ntstatus_to_dos_map search

smb/client: introduce KUnit test to check ntstatus_to_dos_map search

Check whether all elements can be correctly found in the array.

Introduce CONFIG_SMB1_KUNIT_TESTS for smb1maperror_test.ko since
smb1maperror.o is only built when CONFIG_CIFS_ALLOW_INSECURE_LEGACY
is enabled.

We are going to define 3 functions to check the search results, introduce
the macro DEFINE_CHECK_SEARCH_FUNC() to reduce duplicate code.

Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>