s390x/pci: Add missing initialization for g_autofree variables

When declaring g_autofree variable without initialization, 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 initialization for these declarations to prevent the warning and
comply with coding style.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Fixes: cd7498d07fbb ("s390x/pci: Add routine to get the vfio dma available count")
Fixes: 1e7552ff5c34 ("s390x/pci: get zPCI function info from host")
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20210315101352.152888-1-mrezanin@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
index ead4f22..2a153fa 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 @@
  */
 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;