[XEN PATCH v2] x86/iommu_init: address a violation of MISRA C:2012 Rule 8.3

[Federico Serafini <federico.serafini@xxxxxxxxxxx>]

Make function definition and declaration consistent and emphasize that
the formal parameter is deliberately not used.
No functional change.

Signed-off-by: Federico Serafini <federico.serafini@xxxxxxxxxxx>
---
Changes in v2:
- improved code format.
---
 xen/drivers/passthrough/amd/iommu_init.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/amd/iommu_init.c 
b/xen/drivers/passthrough/amd/iommu_init.c
index 9c01a49435..9f955743e1 100644
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -692,7 +692,7 @@ static void iommu_check_ppr_log(struct amd_iommu *iommu)
     spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
-static void cf_check do_amd_iommu_irq(void *unused)
+static void cf_check do_amd_iommu_irq(void *data)
 {
     struct amd_iommu *iommu;
 
@@ -702,6 +702,9 @@ static void cf_check do_amd_iommu_irq(void *unused)
         return;
     }
 
+    /* Formal parameter is deliberately unused. */
+    (void)data;
+
     /*
      * No matter from where the interrupt came from, check all the
      * IOMMUs present in the system. This allows for having just one
-- 
2.34.1