[PATCH 20/20] selftests/vfio: Fix VLA initialisation in vfio_pci_irq_set()

[<mhonap@nvidia.com>]

From: Manish Honap <mhonap@nvidia.com>

C does not permit initialiser expressions on variable-length arrays.
vfio_pci_irq_set() declared

u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count] = {};

where count is a function parameter, making buf a VLA.  GCC rejects
this with "variable-sized object may not be initialized".

Replace the initialiser with an explicit memset() immediately after
the declaration.

Fixes: 19faf6fd969c2 ("vfio: selftests: Add a helper library for VFIO selftests")
Signed-off-by: Manish Honap <mhonap@nvidia.com>
---
 tools/testing/selftests/vfio/lib/vfio_pci_device.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index fac4c0ecadef..3258e814f450 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -26,8 +26,10 @@
 static void vfio_pci_irq_set(struct vfio_pci_device *device,
 			     u32 index, u32 vector, u32 count, int *fds)
 {
-	u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count] = {};
+	u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count];
 	struct vfio_irq_set *irq = (void *)&buf;
+
+	memset(buf, 0, sizeof(buf));
 	int *irq_fds = (void *)&irq->data;
 
 	irq->argsz = sizeof(buf);
-- 
2.25.1