iommu/omap: Clean up bus_set_iommu()

Stop calling bus_set_iommu() since it's now unnecessary, and simplify
the init failure path accordingly.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b578af8e2bf8afeccb2c2ce87c1aa38b36f01331.1660572783.git.robin.murphy@arm.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/omap-iommu.c

@@ -1776,14 +1776,8 @@ static int __init omap_iommu_init(void)
 		goto fail_driver;
 	}
 
-	ret = bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
-	if (ret)
-		goto fail_bus;
-
 	return 0;
 
-fail_bus:
-	platform_driver_unregister(&omap_iommu_driver);
 fail_driver:
 	kmem_cache_destroy(iopte_cachep);
 	return ret;