9pfs: simplify v9fs_walk()

There is only one comparison between nwnames and P9_MAXWELEM required.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1liKiz-0006BC-Ja@lizzy.crudebyte.com>

hw/9pfs/9p.c

@@ -1739,7 +1739,11 @@ static void coroutine_fn v9fs_walk(void *opaque)
 
     trace_v9fs_walk(pdu->tag, pdu->id, fid, newfid, nwnames);
 
-    if (nwnames && nwnames <= P9_MAXWELEM) {
+    if (nwnames > P9_MAXWELEM) {
+        err = -EINVAL;
+        goto out_nofid;
+    }
+    if (nwnames) {
         wnames = g_new0(V9fsString, nwnames);
         qids   = g_new0(V9fsQID, nwnames);
         for (i = 0; i < nwnames; i++) {
@@ -1753,9 +1757,6 @@ static void coroutine_fn v9fs_walk(void *opaque)
             }
             offset += err;
         }
-    } else if (nwnames > P9_MAXWELEM) {
-        err = -EINVAL;
-        goto out_nofid;
     }
     fidp = get_fid(pdu, fid);
     if (fidp == NULL) {