VFS: Unexport do_kern_mount() and clean up simple_pin_fs()

Replace all module uses with the new vfs_kern_mount() interface, and fix up
simple_pin_fs().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/libfs.c b/fs/libfs.c
index 7145ba7..4a3ec9a 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -424,13 +424,13 @@
 
 static DEFINE_SPINLOCK(pin_fs_lock);
 
-int simple_pin_fs(char *name, struct vfsmount **mount, int *count)
+int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count)
 {
 	struct vfsmount *mnt = NULL;
 	spin_lock(&pin_fs_lock);
 	if (unlikely(!*mount)) {
 		spin_unlock(&pin_fs_lock);
-		mnt = do_kern_mount(name, 0, name, NULL);
+		mnt = vfs_kern_mount(type, 0, type->name, NULL);
 		if (IS_ERR(mnt))
 			return PTR_ERR(mnt);
 		spin_lock(&pin_fs_lock);