ANDROID: ABI fixup for abi break in struct dst_ops

In commit 92f1655a ("net: fix __dst_negative_advice() race") the
struct dst_ops callback negative_advice is callback changes function
parameters.  But as this pointer is part of a structure that is tracked
in the ABI checker, the tool triggers when this is changed.

However, the callback pointer is internal to the networking stack, so
changing the function type is safe, so needing to preserve this is not
required.  To do so, switch the function pointer type back to the old
one so that the checking tools pass, AND then do a hard cast of the
function pointer to the new type when assigning and calling the
function.

[6.1.y backport note, work around --Werror=cast-function-type issue by
 abusing void * for function pointer types, despite its best effort, C
 still let's us shoot our foot off if we really want to!]

Bug: 343727534
Bug: 344532797
Fixes: 92f1655a ("net: fix __dst_negative_advice() race")
Change-Id: I48d4ab4bbd29f8edc8fbd7923828b7f78a23e12e
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
(cherry picked from commit a7462d70)