fixing another fabs to abs

Author: scarrazza

src/qcdloop/maths.h

@@ -34,7 +34,7 @@ namespace ql
   inline qcomplex Sqrt(qcomplex const& x){ return csqrtq(x); }
 
   // Absolute value
-  inline double  Abs(double const& x)   { return std::fabs(x); }
+  inline double  Abs(double const& x)   { return std::abs(x); }
   inline qdouble Abs(qdouble const& x)  { return fabsq(x);}
   inline double  Abs(complex const& x)  { return std::abs(x);}
   inline qdouble Abs(qcomplex const& x) { return cabsq(x); }