Eliminate implicit conversion warning in test/array_cwise.cpp
diff --git a/test/array_cwise.cpp b/test/array_cwise.cpp
index 4c6055c..fa087a0 100644
--- a/test/array_cwise.cpp
+++ b/test/array_cwise.cpp
@@ -433,8 +433,8 @@
   VERIFY_IS_APPROX(m3.pow(RealScalar(-2)), m3.square().inverse());
   pow_test<Scalar>();
 
-  VERIFY_IS_APPROX(log10(m3), log(m3)/log(Scalar(10)));
-  VERIFY_IS_APPROX(log2(m3), log(m3)/log(Scalar(2)));
+  VERIFY_IS_APPROX(log10(m3), log(m3)/numext::log(Scalar(10)));
+  VERIFY_IS_APPROX(log2(m3), log(m3)/numext::log(Scalar(2)));
 
   // scalar by array division
   const RealScalar tiny = sqrt(std::numeric_limits<RealScalar>::epsilon());