conf: Fix leak in virNodeDeviceDefParseXML

The 'nodes' is overwritten after the first usage and possibly leaked
if any code in the first set of parsing goes to error.

Found by Coverity.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

src/conf/node_device_conf.c

@@ -1766,7 +1766,7 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
 {
     virNodeDeviceDefPtr def;
     virNodeDevCapsDefPtr *next_cap;
-    xmlNodePtr *nodes;
+    xmlNodePtr *nodes = NULL;
     int n, m;
     size_t i;
 
@@ -1789,7 +1789,6 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
     def->sysfs_path = virXPathString("string(./path[1])", ctxt);
 
     /* Parse devnodes */
-    nodes = NULL;
     if ((n = virXPathNodeSet("./devnode", ctxt, &nodes)) < 0)
         goto error;
 
@@ -1842,7 +1841,7 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
                                             ctxt);
 
     /* Parse device capabilities */
-    nodes = NULL;
+    VIR_FREE(nodes);
     if ((n = virXPathNodeSet("./capability", ctxt, &nodes)) < 0)
         goto error;
 
@@ -1859,10 +1858,8 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
                                               nodes[i],
                                               create,
                                               virt_type);
-        if (!*next_cap) {
-            VIR_FREE(nodes);
+        if (!*next_cap)
             goto error;
-        }
 
         next_cap = &(*next_cap)->next;
     }
@@ -1872,6 +1869,7 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
 
  error:
     virNodeDeviceDefFree(def);
+    VIR_FREE(nodes);
     return NULL;
 }