device.h: Fix struct member documentation

Fix warning of make xmldocs of documention of the struct member iommu_ops from struct bus_type.
Signed-off-by: NMarcos Paulo de Souza <marcos.mage@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

include/linux/device.h

@@ -69,7 +69,7 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  * @resume:	Called to bring a device on this bus out of sleep mode.
  * @pm:		Power management operations of this bus, callback the specific
  *		device driver's pm-ops.
- * @iommu_ops   IOMMU specific operations for this bus, used to attach IOMMU
+ * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
  *              driver implementations to a bus and allow the driver to do
  *              bus-specific setup
  * @p:		The private data of the driver core, only the driver core can