Fix wc(1) output for large files

Previously, we used the System V output format:
	"%7d%7d%7d %s\n"
The problem here is, that if any number has more than six digits, the
result looks like one big number, as we don't mandate spaces.

POSIX says the output format should rather be
	"%d %d %d %s\n"
but in this case we wouldn't get consistent results.

To serve both camps, I changed it to the following:
	"%6d %6d %6d %s\n"
This won't change the output for normal values, but also
prevent the output of large files to be ambiguous.

wc.c

@@ -15,12 +15,21 @@ output(const char *str, size_t nc, size_t nl, size_t nw)
 	int noflags = !cmode && !lflag && !wflag;
 	int first = 1;
 
-	if (lflag || noflags)
-		printf("%*.1zu", first ? (first = 0) : 7, nl);
-	if (wflag || noflags)
-		printf("%*.1zu", first ? (first = 0) : 7, nw);
-	if (cmode || noflags)
-		printf("%*.1zu", first ? (first = 0) : 7, nc);
+	if (lflag || noflags) {
+		if (!first)
+			putchar(' ');
+		printf("%*.1zu", first ? (first = 0) : 6, nl);
+	}
+	if (wflag || noflags) {
+		if (!first)
+			putchar(' ');
+		printf("%*.1zu", first ? (first = 0) : 6, nw);
+	}
+	if (cmode || noflags) {
+		if (!first)
+			putchar(' ');
+		printf("%*.1zu", first ? (first = 0) : 6, nc);
+	}
 	if (str)
 		printf(" %s", str);
 	putchar('\n');