irqdesc: Delete irq_desc_get_msi_desc()

Function irq_desc_get_msi_desc() is not referenced in the kernel (and does
not seem to have been referenced since e39758e, 3 years ago), so
delete it.

Signed-off-by: John Garry <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

Author: John Garry

include/linux/irqdesc.h

@@ -145,11 +145,6 @@ static inline void *irq_desc_get_handler_data(struct irq_desc *desc)
 	return desc->irq_common_data.handler_data;
 }
 
-static inline struct msi_desc *irq_desc_get_msi_desc(struct irq_desc *desc)
-{
-	return desc->irq_common_data.msi_desc;
-}
-
 /*
  * Architectures call this to let the generic IRQ layer
  * handle an interrupt.