liquidio: Use vzalloc()

Use vzalloc() instead of hand writing it with vmalloc()+memset().
This is less verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/93b010824d9d92376e8d49b9eb396a0fa0c0ac80.1685216322.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Paolo Abeni <pabeni@redhat.com>