s3:utils: Fix memory leak in ntlm_auth_diagnostics

s3:utils: Fix memory leak in ntlm_auth_diagnostics

Direct leak of 120 byte(s) in 1 object(s) allocated from:
    #0 0x7f2f7f0fc777 in malloc ../../../../libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x7f2f7ee24c57 in __talloc_with_prefix ../../lib/talloc/talloc.c:783
    #2 0x7f2f7ee26acf in __talloc ../../lib/talloc/talloc.c:825
    #3 0x7f2f7ee26acf in _talloc_named_const ../../lib/talloc/talloc.c:982
    #4 0x7f2f7ee26acf in _talloc_array ../../lib/talloc/talloc.c:2784
    #5 0x7f2f7e3f6a99 in data_blob_talloc_named ../../lib/util/data_blob.c:58
    #6 0x7f2f7e3f6b1b in data_blob_named ../../lib/util/data_blob.c:40
    #7 0x5570b9e36100 in test_lm_ntlm_broken ../../source3/utils/ntlm_auth_diagnostics.c:56
    #8 0x5570b9e36b5d in test_ntlm ../../source3/utils/ntlm_auth_diagnostics.c:180
    #9 0x5570b9e387f3 in diagnose_ntlm_auth ../../source3/utils/ntlm_auth_diagnostics.c:707
    #10 0x5570b9e34efd in main ../../source3/utils/ntlm_auth.c:2855
    #11 0x7f2f7ba2a2ad in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Reviewed-by: Martin Schwenke <martin@meltin.net>