fixed compiler warnings
diff --git a/progs/demos/fire.c b/progs/demos/fire.c
index 056598d..6bf39a5 100644
--- a/progs/demos/fire.c
+++ b/progs/demos/fire.c
@@ -151,7 +151,7 @@
    return (ris / (float) CLOCKS_PER_SEC);
 }
 
-float
+static float
 vrnd(void)
 {
    return (((float) rand()) / RAND_MAX);