Fix type mismatches

Thanks to Random832 for the patch.

du.c

@@ -25,7 +25,7 @@ printpath(off_t n, const char *path)
 	if (hflag)
 		printf("%s\t%s\n", humansize(n * blksize), path);
 	else
-		printf("%ju\t%s\n", n, path);
+		printf("%jd\t%s\n", (intmax_t)n, path);
 }
 
 static off_t

time.c

@@ -36,7 +36,7 @@ main(int argc, char *argv[])
 	if ((ticks = sysconf(_SC_CLK_TCK)) <= 0)
 		eprintf("sysconf _SC_CLK_TCK:");
 
-	if ((r0 = times(&tms)) < 0)
+	if ((r0 = times(&tms)) == (clock_t)-1)
 		eprintf("times:");
 
 	switch ((pid = fork())) {
@@ -52,7 +52,7 @@ main(int argc, char *argv[])
 	}
 	waitpid(pid, &status, 0);
 
-	if ((r1 = times(&tms)) < 0)
+	if ((r1 = times(&tms)) == (clock_t)-1)
 		eprintf("times:");
 
 	if (WIFSIGNALED(status)) {