Alembic export: no need to check particle's mesh_final on export

Hair writing is still not working properly, though, but at least now
samples are written at all.

source/blender/alembic/intern/abc_hair.cc

@@ -72,13 +72,6 @@ void AbcHairWriter::do_write()
 	if (!m_psys) {
 		return;
 	}
-
-	ParticleSystemModifierData *psmd = psys_get_modifier(m_object, m_psys);
-
-	if (!psmd->mesh_final) {
-		return;
-	}
-
 	Mesh *mesh = mesh_get_eval_final(m_settings.depsgraph, m_settings.scene, m_object, CD_MASK_MESH);
 	BKE_mesh_tessface_ensure(mesh);