CIFS: Map SMB2 status codes to POSIX errors

Add mapping table for 32 bit SMB2 status codes to linux errors.
Note that SMB2 does not use DOS/OS2 errors (ever) so mapping to
DOS/OS2 errors as a common network subset (as we do for cifs)
doesn't help. And note that the set of status codes is much more
complete here.

Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>