Increase tolerance for a test in polynomial_test

This test is failing on RawHide due to some compiler
changes.

https://bugzilla.redhat.com/attachment.cgi?id=1046512

Change-Id: I242314a3804b2888f06e5df0a0ea5d3bf057d5df

internal/ceres/polynomial_test.cc

@@ -167,7 +167,7 @@ TEST(Polynomial, QuadraticPolynomialWithTwoNegativeRootsWorks) {
 
 TEST(Polynomial, QuadraticPolynomialWithCloseRootsWorks) {
   const double roots[2] = { 42.42, 42.43 };
-  RunPolynomialTestRealRoots(roots, true, false, kEpsilonLoose);
+  RunPolynomialTestRealRoots(roots, true, false, 2 * psilonLoose);
 }
 
 TEST(Polynomial, QuadraticPolynomialWithComplexRootsWorks) {