Run clang-format on all files

The main change here is to reorder headers.

src/print_help.cpp

@@ -1,12 +1,14 @@
 // Print help message for the specified command.
 #include "config.h"  // IWYU pragma: keep
 
+#include "print_help.h"
+
 #include <stdio.h>
 #include <stdlib.h>
+
 #include <cstring>
 
 #include "common.h"
-#include "print_help.h"
 
 #define CMD_LEN 1024