more fixes for linter

Author: fchapoton

src/sage/algebras/fusion_rings/fusion_double.py

@@ -222,7 +222,7 @@ def _char_cache(self, i, g):
         TESTS::
 
             sage: D = FusionDouble(SymmetricGroup(4))
-            
+
             sage: all(D._char_cache(b.support_of_term(), b.g()) == b.char()(b.g())
             ....:     for b in D.basis())
             True

src/sage/manifolds/differentiable/diff_form.py

@@ -782,7 +782,7 @@ def hodge_dual(
 
         p = self.tensor_type()[1]
         # For performance reasons, we raise the indicies of the volume form
-        # and not of the differential form; in the symplectic case this is wrong by 
+        # and not of the differential form; in the symplectic case this is wrong by
         # a factor of (-1)^p, which will be corrected below
         eps = nondegenerate_tensor.volume_form(p)
         if p == 0:

src/sage/rings/function_field/drinfeld_modules/drinfeld_module.py

@@ -1349,7 +1349,6 @@ def coeff_log(k):
                 return self._base.zero()
         return L(coeff_log, valuation=1)
 
-
     def morphism(self):
         r"""
         Return the morphism object that defines the Drinfeld module.