mlxsw: spectrum_router: Remove abort mechanism

The abort mechanism was introduced in commit 8e05fd71

 ("fib: hook
IPv4 fib for hardware offload") with the purpose of falling back to
software-based routing in case of a route programming error in hardware.
The process is irreversible and requires users to reload the offloading
driver or reboot the machine.

While this approach might make sense in theory, it makes very little
sense in practice. In the case of high speed ASICs such as the Spectrum
ASIC, the abort mechanism effectively kills the machine upon a non-fatal
error such as a route programming error.

Such an extreme policy does not belong in the kernel, especially when
user space can simply try to reprogram the route following the
RTM_NEWROUTE failure notification.

Therefore, remove the abort mechanism.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>