ramfs: Fix use after free in ramfs_remove()

The ramfs_remove_node() will free vp->v_data so we cannot look it up in
ramfs_remove().

Spotted by Coverity.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
ramfs: Fix strlcpy() size in ramfs_rename_node()

Use ->rn_namelen as the destination buffer size for strlcpy().

Spotted by Coverity.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>