progs/tests: Use rand() instead of random().

More portable. Same implementation on Linux.

progs/tests/prog_parameter.c

@@ -116,7 +116,7 @@ static int set_parameter_batch( GLsizei count, GLfloat * param,
 
 
    for ( i = 0 ; i < (4 * count) ; i++ ) {
-      param[i] = (GLfloat) random() / (GLfloat) random();
+      param[i] = (GLfloat) rand() / (GLfloat) rand();
    }
 
    /* Try using the "classic" interface.