Fix various departures from C found by `gcc -ansi -pedantic'. I

haven't checked in Makefile changes to enable this, but I'll at
least fix the specific problems it found when enabled as a one-off.

[originally from svn r5902]

net.c

@@ -120,7 +120,7 @@ static int xyd_cmp(const void *av, const void *bv) {
     if (a->direction > b->direction)
 	return +1;
     return 0;
-};
+}
 
 static int xyd_cmp_nc(void *av, void *bv) { return xyd_cmp(av, bv); }