Fix a kernel crash that occurs when the SMB protocol stack is used. The

Fix a kernel crash that occurs when the SMB protocol stack is used.  The
SMB protocol stack is still hacked to create a kernel thread with a
process structure attached to it (when we really ought to be using a pure
kernel thread... this is the only subsystem that still doesn't).  However,
the SMB code was not properly cleaning the process structure up on exit
resulting in a corrupt process a list.  A 'ps' equivalent occuring after
this situation occurs can crash the kernel.

Reported-by: Rumko <rumcic@gmail.com>