pci-hotplug: initialize dinfo to NULL in pci_device_hot_add

Suppress the following compiler warning emitted by at least gcc version 4.2.1 (SUSE Linux)
and gcc version 3.4.5 (mingw32 special):

hw/pci-hotplug.c: In function 'pci_device_hot_add':
hw/pci-hotplug.c:102: warning: 'dinfo' may be used uninitialized in this function
hw/pci-hotplug.c:102: note: 'dinfo' was declared here
Signed-off-by: NSebastian Herbszt <herbszt@gmx.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/pci-hotplug.c

@@ -99,7 +99,7 @@ static PCIDevice *qemu_pci_hot_add_storage(Monitor *mon,
                                            const char *opts)
 {
     PCIDevice *dev;
-    DriveInfo *dinfo;
+    DriveInfo *dinfo = NULL;
     int type = -1;
     char buf[128];