net:fib-onlink-tests.sh in ubuntu_kernel_selftests failed with FIB table does not exist on KVM kernel

[Po-Hsu Lin]

With CONFIG_DUMMY enabled in bug 1998244 for Jammy+

The net:fib-onlink-tests.sh is now failing with

Running 'make run_tests -C net TEST_PROGS=fib-onlink-tests.sh TEST_GEN_PROGS='' TEST_CUSTOM_PROGS='''
 make: Entering directory '/home/ubuntu/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/net'
 make --no-builtin-rules ARCH=x86 -C ../../../.. headers_install
 make[1]: Entering directory '/home/ubuntu/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
   INSTALL ./usr/include
 make[1]: Leaving directory '/home/ubuntu/autotest/client/tmp/ubuntu_kernel_selftests/src/linux'
 TAP version 13
 1..1
 # selftests: net: fib-onlink-tests.sh
 # Error: ipv4: FIB table does not exist.
 # Flush terminated
 # Error: ipv6: FIB table does not exist.
 # Flush terminated
 #
 # ########################################
 # Configuring interfaces
 # Error: Unknown device type.
 not ok 1 selftests: net: fib-onlink-tests.sh # exit=2

[Po-Hsu Lin (cypressyew)]

Affecting K-kvm as well.