cifs-utils: upgrade to 6.4

6.4 fixed a CVE defect:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-2830


Stack-based buffer overflow in cifskey.c or cifscreds.c in cifs-utils
before 6.4, as used in pam_cifscreds, allows remote attackers to have
unspecified impact via unknown vectors.

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>