tst-fs-link.so: Use mktemp() in check_vnode_duplicity()

Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
vma_fault: propagate exception frame to fault handlers

We suddenly stop propagating the exception frame down the vma_fault path.
There is no reason not to propagate it further, aside from the fact that
currently there are no users. However, aside from the fact that it presents a
more consistent frame passing, I intend to use it for the JVM balloon.

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