[XEN PATCH v2 3/9] x86/irq: tidy switch statement and address MISRA violation

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

Remove unneded blank lines between switch clauses.

Refactor the clauses so that a MISRA C Rule 16.2 violation is resolved
(A switch label shall only be used when the most closely-enclosing
compound statement is the body of a switch statement).
Note that the switch clause ending with the pseudo keyword "fallthrough"
is an allowed exception to Rule 16.3.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
The initialization of irq is due to gcc thinking that irq may be used
uninitizalied in the test after MAP_PIRQ_TYPE_MULTI_MSI
---
 xen/arch/x86/irq.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index 0487f734a5d2..16c023f077da 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -2882,7 +2882,7 @@ int allocate_and_map_gsi_pirq(struct domain *d, int 
index, int *pirq_p)
 int allocate_and_map_msi_pirq(struct domain *d, int index, int *pirq_p,
                               int type, struct msi_info *msi)
 {
-    int irq, pirq, ret;
+    int irq = -1, pirq, ret;
 
     ASSERT_PDEV_LIST_IS_READ_LOCKED(d);
 
@@ -2892,12 +2892,10 @@ int allocate_and_map_msi_pirq(struct domain *d, int 
index, int *pirq_p,
         if ( !msi->table_base )
             msi->entry_nr = 1;
         irq = index;
-        if ( irq == -1 )
-        {
+        fallthrough;
     case MAP_PIRQ_TYPE_MULTI_MSI:
+        if( type == MAP_PIRQ_TYPE_MULTI_MSI || irq == -1 )
             irq = create_irq(NUMA_NO_NODE, true);
-        }
-
         if ( irq < nr_irqs_gsi || irq >= nr_irqs )
         {
             dprintk(XENLOG_G_ERR, "dom%d: can't create irq for msi!\n",
@@ -2905,7 +2903,6 @@ int allocate_and_map_msi_pirq(struct domain *d, int 
index, int *pirq_p,
             return -EINVAL;
         }
         break;
-
     default:
         dprintk(XENLOG_G_ERR, "dom%d: wrong pirq type %x\n",
                 d->domain_id, type);
-- 
2.34.1