[PATCH 2/2] x86/PCI: Slightly simplify pirq_convert_irt_table()

[Christophe JAILLET]

'size' if computed twice. *ir and *it being the same, the result is the
same as well.

While at it, also use struct_size() which is less verbose, more robust and
more informative.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
 arch/x86/pci/irq.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index e29b487cc069..6bc51f80eec2 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -140,14 +140,13 @@ static inline struct irq_routing_table *pirq_convert_irt_table(u8 *addr,
 	if (ir->signature != IRT_SIGNATURE || !ir->used || entries < ir->used)
 		return NULL;
 
-	size = sizeof(*ir) + ir->used * sizeof(ir->slots[0]);
+	size = struct_size(ir, slots, ir->used);
 	if (size > limit - addr)
 		return NULL;
 
 	DBG(KERN_DEBUG "PCI: $IRT Interrupt Routing Table found at 0x%lx\n",
 	    __pa(ir));
 
-	size = sizeof(*rt) + ir->used * sizeof(rt->slots[0]);
 	rt = kzalloc(size, GFP_KERNEL);
 	if (!rt)
 		return NULL;
-- 
2.34.1