Constify source argument of fromhex.

util.c

@@ -197,7 +197,7 @@ parse_thousands(const char *string)
     return -1;
 }
 
-int
+static int
 h2i(char c)
 {
     if(c >= '0' && c <= '9')
@@ -211,7 +211,7 @@ h2i(char c)
 }
 
 int
-fromhex(unsigned char *dest, char *src, int n)
+fromhex(unsigned char *dst, const char *src, int n)
 {
     int i;
     if(n % 2 != 0)
@@ -224,7 +224,7 @@ fromhex(unsigned char *dest, char *src, int n)
         b = h2i(src[i*2 + 1]);
         if(b < 0)
             return -1;
-        dest[i] = a*16 + b;
+        dst[i] = a*16 + b;
     }
     return n/2;
 }

util.h

@@ -79,8 +79,7 @@ void timeval_min(struct timeval *d, const struct timeval *s);
 void timeval_min_sec(struct timeval *d, time_t secs);
 int parse_nat(const char *string) ATTRIBUTE ((pure));
 int parse_thousands(const char *string) ATTRIBUTE ((pure));
-int h2i(char c);
-int fromhex(unsigned char *dest, char *src, int n);
+int fromhex(unsigned char *dst, const char *src, int n);
 void do_debugf(int level, const char *format, ...)
     ATTRIBUTE ((format (printf, 2, 3))) COLD;
 int in_prefix(const unsigned char *restrict address,