Fix rsRand(float, float)

Change-Id: I553d83e1e962ad34aacbe6572d47ff25c3d50060
diff --git a/driver/rsdRuntimeMath.cpp b/driver/rsdRuntimeMath.cpp
index bd1fd0e..093e311 100644
--- a/driver/rsdRuntimeMath.cpp
+++ b/driver/rsdRuntimeMath.cpp
@@ -243,13 +243,15 @@
 static float SC_randf(float max) {
     float r = (float)rand();
     r *= max;
-    return r / RAND_MAX;
+    r /= RAND_MAX;
+    return r;
 }
 
 static float SC_randf2(float min, float max) {
     float r = (float)rand();
+    r /= RAND_MAX;
     r = r * (max - min) + min;
-    return r / RAND_MAX;
+    return r;
 }
 
 static int SC_randi(int max) {