conf: Fix initialization value of 'multi' in PCI address

The 'multi' element in PCI address struct used as 'virTristateSwitch',
and its default value is 'VIR_TRISTATE_SWITCH_ABSENT'. Current PCI
process use 'false' to initialization 'multi', which is ambiguously
for assignment or comparison. This patch use '{0}' to initialize
the whole PCI address struct, which fix the 'multi' initialization
and makes code more simplify and explicitly.
Signed-off-by: NXian Han Yu <xhyubj@linux.vnet.ibm.com>

src/conf/domain_addr.c

@@ -590,7 +590,7 @@ virDomainPCIAddressGetNextSlot(virDomainPCIAddressSetPtr addrs,
     /* default to starting the search for a free slot from
      * the first slot of domain 0 bus 0...
      */
-    virPCIDeviceAddress a = { 0, 0, 0, 0, false };
+    virPCIDeviceAddress a = {0};
     char *addrStr = NULL;
 
     if (addrs->nbuses == 0) {

src/conf/node_device_conf.c

@@ -1164,7 +1164,7 @@ virNodeDevCapPCIDevIommuGroupParseXML(xmlXPathContextPtr ctxt,
         goto cleanup;
 
     for (i = 0; i < nAddrNodes; i++) {
-        virPCIDeviceAddress addr = { 0, 0, 0, 0, 0 };
+        virPCIDeviceAddress addr = {0};
         if (virPCIDeviceAddressParseXML(addrNodes[i], &addr) < 0)
             goto cleanup;
         if (VIR_ALLOC(pciAddr) < 0)

src/qemu/qemu_domain_address.c

@@ -1096,7 +1096,7 @@ qemuDomainAssignDevicePCISlots(virDomainDefPtr def,
 
         /* USB2 needs special handling to put all companions in the same slot */
         if (IS_USB2_CONTROLLER(def->controllers[i])) {
-            virPCIDeviceAddress addr = { 0, 0, 0, 0, false };
+            virPCIDeviceAddress addr = {0};
             bool foundAddr = false;
 
             memset(&tmp_addr, 0, sizeof(tmp_addr));