hw/9pfs: Use export_flag for indicating whether fs driver use path names.

This allows us to remove another member from the struct

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index ad2d841..0bb4cad 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -702,7 +702,7 @@
     int err;
     struct statfs stbuf;
 
-    ctx->flags |= PATHNAME_FSCONTEXT;
+    ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
     err = statfs(ctx->fs_root, &stbuf);
     if (!err) {
         switch (stbuf.f_type) {