This deals with a sun4c issue caused by commit b6a2fea393:
mm: variable length argument support.
The new way the code works means that sun4c_update_mmu_cache gets
called before a context has been selected, which results in invalid
operation of the underling mm code.
Simply ignoring update requests when there is no valid context solves
the problem.
Signed-off-by Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>