fs/vfs/symlink: fix the inode information update outside of lock

For re-enter case, the inode information may unlock with not filled,
and get by other user. that lead to the error behavior.
Especially SMP scene.

Signed-off-by: buxiasen <buxiasen@xiaomi.com>

fs/vfs/fs_symlink.c

@@ -146,6 +146,15 @@ int symlink(FAR const char *path1, FAR const char *path2)
 
       inode_lock();
       ret = inode_reserve(path2, 0777, &inode);
+
+      if (ret >= 0)
+        {
+          /* Initialize the inode */
+
+          INODE_SET_SOFTLINK(inode);
+          inode->u.i_link = newpath2;
+        }
+
       inode_unlock();
       if (ret < 0)
         {
@@ -153,11 +162,6 @@ int symlink(FAR const char *path1, FAR const char *path2)
           errcode = -ret;
           goto errout_with_search;
         }
-
-      /* Initialize the inode */
-
-      INODE_SET_SOFTLINK(inode);
-      inode->u.i_link = newpath2;
     }
 
   /* Symbolic link successfully created */