storage: backend: Log uid/gid when initializing storage file backend

To ease debugging permission problems add uid/gid values to the debug
message when initializing a storage file backend.

src/storage/storage_backend_fs.c

@@ -1370,9 +1370,10 @@ virStorageFileBackendFileInit(virStorageSourcePtr src)
 {
     virStorageFileBackendFsPrivPtr priv = NULL;
 
-    VIR_DEBUG("initializing FS storage file %p (%s:%s)", src,
+    VIR_DEBUG("initializing FS storage file %p (%s:%s)[%u:%u]", src,
               virStorageTypeToString(virStorageSourceGetActualType(src)),
-              src->path);
+              src->path,
+              (unsigned int)src->drv->uid, (unsigned int)src->drv->gid);
 
     if (VIR_ALLOC(priv) < 0)
         return -1;

src/storage/storage_backend_gluster.c

@@ -582,9 +582,10 @@ virStorageFileBackendGlusterInit(virStorageSourcePtr src)
 
     hostname = host->name;
 
-    VIR_DEBUG("initializing gluster storage file %p (gluster://%s:%s/%s%s)",
+    VIR_DEBUG("initializing gluster storage file %p (gluster://%s:%s/%s%s)[%u:%u]",
               src, hostname, host->port ? host->port : "0",
-              NULLSTR(src->volume), src->path);
+              NULLSTR(src->volume), src->path,
+              (unsigned int)src->drv->uid, (unsigned int)src->drv->gid);
 
     if (!src->volume) {
         virReportError(VIR_ERR_INTERNAL_ERROR,