Remove unused global variable (#4189)

* Remove unused global variable

Author: deepsource-autofix[bot]

tests/test_rand_affine_grid.py

@@ -18,7 +18,7 @@
 from monai.transforms import RandAffineGrid
 from tests.utils import TEST_NDARRAYS, assert_allclose, is_tf32_env
 
-_rtol = 1e-1 if is_tf32_env else 1e-4
+_rtol = 1e-1 if is_tf32_env() else 1e-4
 
 TESTS = []
 for p in TEST_NDARRAYS:

tests/utils.py

@@ -586,13 +586,11 @@ def _wrapper(*args, **kwargs):
 
 def _cache_original_func(obj) -> None:
     """cache the original function by name, so that the decorator doesn't shadow it."""
-    global _original_funcs
     _original_funcs[obj.__name__] = obj
 
 
 def _del_original_func(obj):
     """pop the original function from cache."""
-    global _original_funcs
     _original_funcs.pop(obj.__name__, None)
     if torch.cuda.is_available():  # clean up the cached function
         torch.cuda.synchronize()