Fix typo in docstring (#15121)

it -> int

Author: birdsarah

pandas/util/testing.py

@@ -1220,7 +1220,7 @@ def assert_frame_equal(left, right, check_dtype=True,
         are identical.
     check_frame_type : bool, default False
         Whether to check the DataFrame class is identical.
-    check_less_precise : bool or it, default False
+    check_less_precise : bool or int, default False
         Specify comparison precision. Only used when check_exact is False.
         5 digits (False) or 3 digits (True) after decimal points are compared.
         If int, then specify the digits to compare