[PATCH v3] Add missing initialization for g_autofree variables

[mrezanin]

From: Miroslav Rezanina <mrezanin@redhat.com>

When declaring g_autofree variable without inicialization, compiler
will raise "may be used uninitialized in this function" warning due
to automatic free handling.

This is mentioned in docs/devel/style.rst (quote from section
"Automatic memory deallocation"):

  * Variables declared with g_auto* MUST always be initialized,
    otherwise the cleanup function will use uninitialized stack memory

Add inicialization for these declarations to prevent the warning and
comply with coding style.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---
* v3:
  -- allocate in s390_pci_update_dma_avail instead of NULL init

* v2:
  -- Removed fixes in hw/remote/memory.c and hw/remote/proxy.c
     fixed by patch sent by Zenghui Yu (multi-process: Initialize
     variables declared with g_auto*)
---
 hw/s390x/s390-pci-vfio.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
index ead4f222d5..2a153fa8c9 100644
--- a/hw/s390x/s390-pci-vfio.c
+++ b/hw/s390x/s390-pci-vfio.c
@@ -29,14 +29,11 @@
  */
 bool s390_pci_update_dma_avail(int fd, unsigned int *avail)
 {
-    g_autofree struct vfio_iommu_type1_info *info;
-    uint32_t argsz;
+    uint32_t argsz = sizeof(struct vfio_iommu_type1_info);
+    g_autofree struct vfio_iommu_type1_info *info = g_malloc0(argsz);
 
     assert(avail);
 
-    argsz = sizeof(struct vfio_iommu_type1_info);
-    info = g_malloc0(argsz);
-
     /*
      * If the specified argsz is not large enough to contain all capabilities
      * it will be updated upon return from the ioctl.  Retry until we have
@@ -230,7 +227,7 @@ static void s390_pci_read_pfip(S390PCIBusDevice *pbdev,
  */
 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev)
 {
-    g_autofree struct vfio_device_info *info;
+    g_autofree struct vfio_device_info *info = NULL;
     VFIOPCIDevice *vfio_pci;
     uint32_t argsz;
     int fd;
-- 
2.27.0