!718 [LTS-3.0]修复jffs2适配层错误释放锁的BUG

Merge pull request !718 from Far/cherry-pick-1637906208

fs/jffs2/src/vfs_jffs2.c

@@ -201,13 +201,13 @@ int VfsJffs2Lookup(struct Vnode *parentVnode, const char *path, int len, struct
     }
 
     (void)VfsHashGet(parentVnode->originMount, node->i_ino, &newVnode, NULL, NULL);
-    LOS_MuxUnlock(&g_jffs2FsLock);
     if (newVnode) {
         if (newVnode->data == NULL) {
             LOS_Panic("#####VfsHashGet error#####\n");
         }
         newVnode->parent = parentVnode;
         *ppVnode = newVnode;
+        LOS_MuxUnlock(&g_jffs2FsLock);
         return 0;
     }
     ret = VnodeAlloc(&g_jffs2Vops, &newVnode);