dma-mapping: no need to pass a bus_type into get_arch_dma_ops()

The get_arch_dma_ops() arch-specific function never does anything with
the struct bus_type that is passed into it, so remove it entirely as it
is not needed.

Cc: Richard Henderson <[e-mail]>
Cc: Ivan Kokshaysky <[e-mail]>
Cc: Matt Turner <[e-mail]>
Cc: Thomas Bogendoerfer <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: Helge Deller <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: [e-mail]
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Marek Szyprowski <[e-mail]>
Cc: Robin Murphy <[e-mail]>
Cc: Konrad Rzeszutek Wilk <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Acked-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

arch/alpha/include/asm/dma-mapping.h

···
 
 extern const struct dma_map_ops alpha_pci_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 #ifdef CONFIG_ALPHA_JENSEN
 	return NULL;

arch/ia64/include/asm/dma-mapping.h

···
  */
 extern const struct dma_map_ops *dma_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 	return dma_ops;
 }

arch/mips/include/asm/dma-mapping.h

···
 
 extern const struct dma_map_ops jazz_dma_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 #if defined(CONFIG_MACH_JAZZ)
 	return &jazz_dma_ops;

arch/parisc/include/asm/dma-mapping.h

···
 
 extern const struct dma_map_ops *hppa_dma_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 	return hppa_dma_ops;
 }

arch/sparc/include/asm/dma-mapping.h

···
 
 extern const struct dma_map_ops *dma_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 	/* sparc32 uses per-device dma_ops */
 	return IS_ENABLED(CONFIG_SPARC64) ? dma_ops : NULL;

arch/x86/include/asm/dma-mapping.h

···
 
 extern const struct dma_map_ops *dma_ops;
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 	return dma_ops;
 }

include/asm-generic/dma-mapping.h

···
 #ifndef _ASM_GENERIC_DMA_MAPPING_H
 #define _ASM_GENERIC_DMA_MAPPING_H
 
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+static inline const struct dma_map_ops *get_arch_dma_ops(void)
 {
 	return NULL;
 }

include/linux/dma-map-ops.h

···
 {
 	if (dev->dma_ops)
 		return dev->dma_ops;
-	return get_arch_dma_ops(dev->bus);
+	return get_arch_dma_ops();
 }
 
 static inline void set_dma_ops(struct device *dev,