Make roughly work with unsigned values.

util.c

@@ -63,8 +63,8 @@ seqno_plus(unsigned short s, int plus)
     return ((s + plus) & 0xFFFF);
 }
 
-int
-roughly(int value)
+unsigned
+roughly(unsigned value)
 {
     return value * 3 / 4 + random() % (value / 2);
 }

util.h

@@ -43,7 +43,7 @@ int seqno_minus(unsigned short s1, unsigned short s2)
     ATTRIBUTE ((const));
 unsigned short seqno_plus(unsigned short s, int plus)
     ATTRIBUTE ((const));
-int roughly(int value);
+unsigned roughly(unsigned value);
 void timeval_minus(struct timeval *d,
                    const struct timeval *s1, const struct timeval *s2);
 int timeval_minus_msec(const struct timeval *s1, const struct timeval *s2)