Linux: 2.6.37 - replace get_sb with mount

Linux: 2.6.37 - replace get_sb with mount

With kernel 2.6.37 the new entry point for mounting a filesystem
is the mount() operation instead of get_sb().

Replace afs_get_sb with afs_mount if the new operation is
available, and use mount_nodev instead of get_sb_nodev.

Note that this is not strictly required for 2.6.37 since the old
interfaces are still around, but we might as well switch now.

Reviewed-on: http://gerrit.openafs.org/3245
Reviewed-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 2ea841feac2de8ade987c18cb7043aacfebe0d83)
Change-Id: I1f17068a1a06654568f30b75c5c65da0100995cd
Reviewed-on: http://gerrit.openafs.org/3251