kernel: cifs: Fix a kernel BUG with remote OS/2 server

fs/cifs/cifssmb.c in the CIFS implementation in the Linux kernel before 2.6.34-rc4 allows remote attackers to cause a denial of service panic via an SMB response packet with an invalid CountHigh value, as demonstrated by a response from an OS/2 server, related to the CIFSSMBWrite and CIFSSMBWrite...