ACPI: OSL: Make a W=1 kernel-doc warning go away

It appears that kernel-doc does not understand the return type *__ref,

drivers/acpi/osl.c:306: warning: cannot understand function prototype:
'void __iomem *__ref acpi_os_map_iomem(acpi_physical_address phys,
acpi_size size)
Signed-off-by: Qian Cai <cai@lca.pw>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/osl.c

@@ -301,8 +301,8 @@ static void acpi_unmap(acpi_physical_address pg_off, void __iomem *vaddr)
  * During early init (when acpi_permanent_mmap has not been set yet) this
  * routine simply calls __acpi_map_table() to get the job done.
  */
-void __iomem *__ref
-acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
+void __iomem __ref
+*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size)
 {
 	struct acpi_ioremap *map;
 	void __iomem *virt;

include/acpi/acpi_io.h

@@ -16,8 +16,8 @@ static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
 
 extern bool acpi_permanent_mmap;
 
-void __iomem *__ref
-acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
+void __iomem __ref
+*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
 void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
 void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);