reverse-ramdisk.c: sort includes

c-programming/reverse-ramdisk.c

@@ -14,10 +14,10 @@ To-Do: error handling on line 167, function fread()
 
 #include <errno.h>
 #include <inttypes.h>
+#include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <math.h>
 
 #ifdef DEBUG
 # define line_fail(x) do { \