bpfilter: Move bpfilter_umh back into init data

bpfilter: Move bpfilter_umh back into init data

To allow for restarts 61fbf5933d42 ("net: bpfilter: restart
bpfilter_umh when error occurred") moved the blob holding the
userspace binary out of the init sections.

Now that loading the blob into a filesystem is separate from executing
the blob the blob no longer needs to live .rodata to allow for restarting.
So move the blob back to .init.rodata.

v1: https://lkml.kernel.org/r/87sgeidlvq.fsf_-_@x220.int.ebiederm.org
v2: https://lkml.kernel.org/r/87ftad4ozc.fsf_-_@x220.int.ebiederm.org
Link: https://lkml.kernel.org/r/20200702164140.4468-11-ebiederm@xmission.com
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>