PR #43819: Fix operator check

Imported from GitHub PR https://github.com/tensorflow/tensorflow/pull/43819

Fixes https://github.com/tensorflow/tensorflow/issues/43817
Copybara import of the project:

--
bd1f1ac1fe by bhack <bhack@users.noreply.github.com>:

Fix operator check

PiperOrigin-RevId: 335934604
Change-Id: I6cfc4d218d5cd8dfb00ce6c72dbecb8afa91ede9

tensorflow/python/ops/linalg/registrations_util.py

@@ -56,7 +56,7 @@ def is_square(operator_a, operator_b):
       return m == l
 
   if (operator_a.is_square != operator_b.is_square) and (
-      operator_a.is_square is not None and operator_a.is_square is not None):
+      operator_a.is_square is not None and operator_b.is_square is not None):
     return False
 
   return None