tests: Replace Mul with UnevalMul

Author: EdCaunt

tests/test_symbolics.py

@@ -15,7 +15,7 @@
                               INT, FieldFromComposite, IntDiv, Namespace, Rvalue,
                               ReservedWord, ListInitializer, uxreplace, pow_to_mul,
                               retrieve_derivatives, BaseCast)
-from devito.symbolics.unevaluation import Mul
+from devito.symbolics.unevaluation import Mul as UnevalMul
 from devito.tools import as_tuple
 from devito.types import (Array, Bundle, FIndexed, LocalObject, Object,
                           ComponentAccess, StencilDimension, Symbol as dSymbol)
@@ -880,7 +880,7 @@ def test_assumptions(self, op, expr, assumptions, expected):
 def test_issue_2577():
 
     u = TimeFunction(name='u', grid=Grid((2,)))
-    eq = Eq(u.forward, Mul(-1, -1., u))
+    eq = Eq(u.forward, UnevalMul(-1, -1., u))
     op = Operator(eq)
 
     assert '--' not in str(op.ccode)