block/gluster: Add missing argument to qemu_gluster_init() call

Commit adccfbcd (block: gluster - add
reopen support.) did not supply the qemu_gluster_init() Error **
argument, needed since commit a7451cb8
(gluster: correctly propagate errors).

Pass through qemu_gluster_reopen_prepare()'s errp, as done in
qemu_gluster_open().

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

block/gluster.c

@@ -364,7 +364,7 @@ static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
 
     gconf = g_malloc0(sizeof(GlusterConf));
 
-    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename);
+    reop_s->glfs = qemu_gluster_init(gconf, state->bs->filename, errp);
     if (reop_s->glfs == NULL) {
         ret = -errno;
         goto exit;