needed for mem* funcs

--- a/libhfsp/src/unicode.c
+++ b/libhfsp/src/unicode.c
@@ -16,7 +16,7 @@
 #include <stdlib.h>
 #include <endian.h>
 #include <byteswap.h>
-#include <linux/string.h>
+#include <string.h>
 
 #define __USE_GNU
     /* need wcsrtomb */
--- a/libhfsp/src/partitions.c
+++ b/libhfsp/src/partitions.c
@@ -31,6 +31,7 @@
 #include "os.h"
 #include "libhfsp.h"
 
+#include <string.h>
 #include <stdlib.h>
 
 /*
--- a/libhfsp/src/record.c
+++ b/libhfsp/src/record.c
@@ -32,6 +32,7 @@
 
 #include <errno.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "libhfsp.h"
 #include "hfstime.h"