Handle big endianness in NTLM (ntlmv2) authentication

commit fdf96a907c1fbb93c633e2b7ede3b8df26d6a4c0 upstream.

This is RH bug 970891
Uppercasing of username during calculation of ntlmv2 hash fails
because UniStrupr function does not handle big endian wchars.

Also fix a comment in the same code to reflect its correct usage.

[To make it easier for stable (rather than require 2nd patch) fixed
this patch of Shirish's to remove endian warning generated
by sparse -- steve f.]

Reported-by: steve <sanpatr1@in.ibm.com>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>