ipvs: use GFP_KERNEL allocation where possible

Use GFP_KERNEL instead of GFP_ATOMIC when registering an ipvs protocol.

This is safe since it will always run from a process context.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>