Initialized force in default single()

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@9274 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/pair.h

@@ -124,7 +124,11 @@ class Pair : protected Pointers {
   virtual void compute_outer(int, int) {}
 
   virtual double single(int, int, int, int,
-                        double, double, double, double &) {return 0.0;}
+                        double, double, double, 
+			double& fforce) {
+    fforce = 0.0;
+    return 0.0;
+  }
 
   virtual void settings(int, char **) = 0;
   virtual void coeff(int, char **) = 0;