node: Replace variable named 'system' with 'syscap'

Changes in commit id 'dec6d9df' caused a compilation failure on a RHEL6
CI build environment. So just replace 'system' with 'syscap' as a name.

cc1: warnings being treated as errors
../../src/conf/node_device_conf.c: In function 'virNodeDevCapSystemParseXML':
../../src/conf/node_device_conf.c:1415: error: declaration of 'system' shadows a global declaration [-Wshadow]

src/conf/node_device_conf.c

@@ -1412,10 +1412,10 @@ static int
 virNodeDevCapSystemParseXML(xmlXPathContextPtr ctxt,
                             virNodeDeviceDefPtr def,
                             xmlNodePtr node,
-                            virNodeDevCapSystemPtr system)
+                            virNodeDevCapSystemPtr syscap)
 {
-    virNodeDevCapSystemHardwarePtr hardware = &system->hardware;
-    virNodeDevCapSystemFirmwarePtr firmware = &system->firmware;
+    virNodeDevCapSystemHardwarePtr hardware = &syscap->hardware;
+    virNodeDevCapSystemFirmwarePtr firmware = &syscap->firmware;
     xmlNodePtr orignode;
     int ret = -1;
     char *tmp;
@@ -1423,7 +1423,7 @@ virNodeDevCapSystemParseXML(xmlXPathContextPtr ctxt,
     orignode = ctxt->node;
     ctxt->node = node;
 
-    system->product_name = virXPathString("string(./product[1])", ctxt);
+    syscap->product_name = virXPathString("string(./product[1])", ctxt);
 
     hardware->vendor_name = virXPathString("string(./hardware/vendor[1])", ctxt);
     hardware->version     = virXPathString("string(./hardware/version[1])", ctxt);

src/node_device/node_device_udev.c

@@ -1420,12 +1420,12 @@ static void udevEventHandleCallback(int watch ATTRIBUTE_UNUSED,
 /* DMI is intel-compatible specific */
 #if defined(__x86_64__) || defined(__i386__) || defined(__amd64__)
 static void
-udevGetDMIData(virNodeDevCapSystemPtr system)
+udevGetDMIData(virNodeDevCapSystemPtr syscap)
 {
     struct udev *udev = NULL;
     struct udev_device *device = NULL;
-    virNodeDevCapSystemHardwarePtr hardware = &system->hardware;
-    virNodeDevCapSystemFirmwarePtr firmware = &system->firmware;
+    virNodeDevCapSystemHardwarePtr hardware = &syscap->hardware;
+    virNodeDevCapSystemFirmwarePtr firmware = &syscap->firmware;
 
     udev = udev_monitor_get_udev(DRV_STATE_UDEV_MONITOR(driver));
 
@@ -1441,7 +1441,7 @@ udevGetDMIData(virNodeDevCapSystemPtr system)
     }
 
     if (udevGetStringSysfsAttr(device, "product_name",
-                               &system->product_name) < 0)
+                               &syscap->product_name) < 0)
         goto cleanup;
     if (udevGetStringSysfsAttr(device, "sys_vendor",
                                &hardware->vendor_name) < 0)