libxl: Avoid a variable named 'stat'

Using a variable named 'stat' clashes with the system function
'stat()' causing compiler warnings on some platforms:

libxl/libxl_driver.c: In function 'libxlDomainBlockStatsVBD':
libxl/libxl_driver.c:5387: error: declaration of 'stat' shadows a global declaration [-Wshadow]
/usr/include/sys/stat.h:455: error: shadowed declaration is here [-Wshadow]
Signed-off-by: NGeorge Dunlap <george.dunlap@citrix.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

src/libxl/libxl_driver.c

@@ -5374,7 +5374,7 @@ libxlDomainBlockStatsVBD(virDomainObjPtr vm,
     int devno = libxlDiskPathToID(dev);
     int size;
     char *path, *name, *val;
-    unsigned long long stat;
+    unsigned long long status;
 
     path = name = val = NULL;
     if (devno < 0) {
@@ -5401,12 +5401,12 @@ libxlDomainBlockStatsVBD(virDomainObjPtr vm,
 # define LIBXL_SET_VBDSTAT(FIELD, VAR, MUL)           \
     if ((virAsprintf(&name, "%s/"FIELD, path) < 0) || \
         (virFileReadAll(name, 256, &val) < 0) ||      \
-        (sscanf(val, "%llu", &stat) != 1)) {          \
+        (sscanf(val, "%llu", &status) != 1)) {        \
         virReportError(VIR_ERR_OPERATION_FAILED,      \
                        _("cannot read %s"), name);    \
         goto cleanup;                                 \
     }                                                 \
-    VAR += (stat * MUL);                              \
+    VAR += (status * MUL);                            \
     VIR_FREE(name);                                   \
     VIR_FREE(val);