Fixed error in mixed precision mode

platforms/opencl/src/kernels/andersenThermostat.cl

@@ -4,8 +4,8 @@
 
 __kernel void applyAndersenThermostat(float collisionFrequency, float kT, __global mixed4* velm, __global const mixed2* restrict stepSize, __global const float4* restrict random,
         unsigned int randomIndex, __global const int* restrict atomGroups) {
-    float collisionProbability = 1.0f-EXP(-collisionFrequency*stepSize[0].y);
-    float randomRange = erf(collisionProbability/SQRT(2.0f));
+    float collisionProbability = (float) (1.0f-exp(-collisionFrequency*stepSize[0].y));
+    float randomRange = (float) erf(collisionProbability/exp(2.0f));
     for (int index = get_global_id(0); index < NUM_ATOMS; index += get_global_size(0)) {
         mixed4 velocity = velm[index];
         float4 selectRand = random[randomIndex+atomGroups[index]];