ufs: copy symlink data into the correct union member

Copy symlink data into the union member it is accessed through. Although
this shouldn't make a difference to behaviour it makes the code easier
to follow and grep through. It may also prevent problems if the
struct/union definitions change in the future.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>