Older versions of nfs utils don't always pass a "vers=" mount option for
NFS.  This chould lead to attempts at using NFS v0 due to a zeroed out
nfs_parsed_mount_data struct.  I solve this by setting the default NFS
version to NFS_DEFAULT_VERSION in the v2 and v3 cases (v4 has already been
taken care of by a similar patch).
Reported-by: NJoerg Roedel <joro@&amp;bytes.org>
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>