Move path_root check up so path() and get_mnt_sb() can be avoided in the cases _do_get_path() fails.

volatility3/framework/plugins/linux/mountinfo.py

@@ -89,6 +89,10 @@ class MountInfo(plugins.PluginInterface):
         if not mnt_root:
             return None
 
+        path_root = cls._do_get_path(mnt, task.fs.root)
+        if path_root is None:
+            return None
+
         mnt_root_path = mnt_root.path()
         superblock = mnt.get_mnt_sb()
 
@@ -97,10 +101,6 @@ class MountInfo(plugins.PluginInterface):
 
         st_dev = f"{superblock.major}:{superblock.minor}"
 
-        path_root = cls._do_get_path(mnt, task.fs.root)
-        if path_root is None:
-            return None
-
         mnt_opts: List[str] = []
         mnt_opts.append(mnt.get_flags_access())
         mnt_opts.extend(mnt.get_flags_opts())