include: error: Add enum sentinel for virErrorNumber enum

We do have one for the error domain but not for the error number itself.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>

include/libvirt/virterror.h

@@ -321,6 +321,11 @@ typedef enum {
     VIR_ERR_DEVICE_MISSING = 99,        /* fail to find the desired device */
     VIR_ERR_INVALID_NWFILTER_BINDING = 100,  /* invalid nwfilter binding */
     VIR_ERR_NO_NWFILTER_BINDING = 101,  /* no nwfilter binding */
+
+# ifdef VIR_ENUM_SENTINELS
+    VIR_ERR_NUMBER_LAST
+# endif
+
 } virErrorNumber;
 
 /**

src/util/virerror.c

@@ -914,6 +914,7 @@ virErrorMsg(virErrorNumber error, const char *info)
     const char *errmsg = NULL;
 
     switch (error) {
+        case VIR_ERR_NUMBER_LAST:
         case VIR_ERR_OK:
             return NULL;
         case VIR_ERR_INTERNAL_ERROR: