Allocate hex map with the trailing NULL

Compilers usually warns or errors on such allocations. This would require
special compiler parameters or attribute to silence it. Unfortunately, it is
compiler specific, e.g. with gcc one could use "__attribute__ ((nonstring))"
or with C23 just "[[nonstring]]" or gcc parameter
"-Wno-error=unterminated-string-initialization". With other compilers
it's different. So do not over-complicate things and allocate it just one
more byte longer with the dummy NULL which should silence most of the
compilers. It's static allocation, just one byte, the overhead should be
negligible.

Signed-off-by: Jaroslav Škarvada <jskarvad@redhat.com>

Author: yarda

lib/util/hex.c

@@ -84,7 +84,7 @@ hidrd_hex_buf_from_str(void        *buf,
 char *
 hidrd_hex_buf_to_str(const void *buf, size_t size)
 {
-    static const char   map[16] = "0123456789ABCDEF";
+    static const char   map[17] = "0123456789ABCDEF";
     const uint8_t      *bbuf    = (const uint8_t *)buf;
     char               *str;
     char               *p;