fix: had to include linux/string.h so thath DEBUG_FMT would work

proto/debug/debug.h

 #pragma once
 #include <linux/kernel.h>
 #include <linux/printk.h>
+#include <linux/string.h>
 
 // This GCC extension removes the trailing comma when __VA_ARGS__ is empty. This
 // ensures the macro works whether or not extra arguments are provided.