Fix invalid call to __host__ function in computeBondedForces

Explicitly cast the second parameter to the type of the first one so the compiler can pick an overload that is supported in device code (fixes error: calling a __host__ function("fmin<float, int, (int)0> ") from a __global__ function("computeBondedForces") is not allowed).

platforms/common/src/kernels/cmapTorsionForce.cc

@@ -61,8 +61,8 @@ angleB = fmod(angleB+2.0f*PI, 2.0f*PI);
 int2 pos = MAP_POS[MAPS[index]];
 int size = pos.y;
 real delta = 2*PI/size;
-int s = (int) fmin(angleA/delta, size-1);
-int t = (int) fmin(angleB/delta, size-1);
+int s = (int) fmin(angleA/delta, (real) (size-1));
+int t = (int) fmin(angleB/delta, (real) (size-1));
 float4 c[4];
 int coeffIndex = pos.x+4*(s+size*t);
 c[0] = COEFF[coeffIndex];