Fix AttributeError after transforming ParticleAttributeNode
Fix AttributeError after transforming ParticleAttributeNode

Once we transform ParticleAttributeNode to a bare IntrinsicNode, we
can't look at the func attribute. The check for a FieldEvalCallNode
should be a separate branch of the same conditional.

OceanPARCELS/parcels,OceanPARCELS/parcels