If tunnel registration failed during module initialization, the module
would fail to deregister the IPPROTO_COMP protocol and would attempt to
deregister the tunnel.
The tunnel was not deregistered during module-exit.
Fixes: 125bb8f0a4279 ("vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel") Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>