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.c b/hw/9pfs/virtio-9p.c
index b0a87c8..aab3beb 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -2493,7 +2493,7 @@
         goto out_nofid;
     }
     /* if fs driver is not path based, return EOPNOTSUPP */
-    if (!pdu->s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) {
         err = -EOPNOTSUPP;
         goto out_err;
     }
@@ -2640,7 +2640,7 @@
     }
     BUG_ON(fidp->fid_type != P9_FID_NONE);
     /* if fs driver is not path based, return EOPNOTSUPP */
-    if (!pdu->s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) {
         err = -EOPNOTSUPP;
         goto out;
     }
@@ -2713,7 +2713,7 @@
     if (err < 0) {
         goto out;
     }
-    if (s->ctx.flags & PATHNAME_FSCONTEXT) {
+    if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
         /* Only for path based fid  we need to do the below fixup */
         v9fs_fix_fid_paths(pdu, &olddirfidp->path, old_name,
                            &newdirfidp->path, new_name);