fix "struct irq_desc"

In linux-2.6.0-test2-ia64-030729 configured for generic ia64, asm-ia64/machvec.h returns a 'struct irq_desc'. There is a forward declaration for the struct, but it is never actually defined under that name, only as irq_desc_t.

This means that the type of ia64_mv_irq_desc is wrong, which causes the build to break in some files that are built with -Werror. Really this is incorrect even for non-generic builds although it does not actually fail.

This patch puts in both the struct name and _t name:

@@ -56,7 +56,7 @@ typedef struct hw_interrupt_type  hw_irq
  *
  * Pad this out to 32 bytes for cache and indexing reasons.
  */
-typedef struct {
+typedef struct irq_desc {
 	unsigned int status;		/* IRQ status */
 	hw_irq_controller *handler;
 	struct irqaction *action;	/* IRQ action list */

Perhaps it would be better to make everything use the irq_desc_t name? That would require a somewhat larger rearrangement of the headers to make it visible at that point, but I can do that if desired.

Martin