Fix NULL-dereference added in rev.12779

Fix NULL-dereference added in rev.12779

With the change of helper responses from Notes to NotePairs the errNote
in NTLM ERR/NA responses was altered to a potentially NULL char*, and
allowed to be printed in debugs() level 4.

This updated NTLM and Negotiate halpers to print the helper response as
"Result: ..." in identical fashion.

  Detected by Coverity Scan. Issue 1020655.