selftests/nolibc: make result alignment more robust

Move the check of the existing length into the function so it can't be
forgotten by the caller.

Also hardcode the padding character as only spaces are ever used.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

tools/testing/selftests/nolibc/nolibc-test.c

@@ -130,11 +130,17 @@ static const char *errorname(int err)
 	}
 }
 
-static void putcharn(char c, size_t n)
+static void align_result(size_t llen)
 {
-	char buf[64];
+	const size_t align = 64;
+	char buf[align];
+	size_t n;
 
-	memset(buf, c, n);
+	if (llen >= align)
+		return;
+
+	n = align - llen;
+	memset(buf, ' ', n);
 	buf[n] = '\0';
 	fputs(buf, stdout);
 }
@@ -156,8 +162,7 @@ static void result(int llen, enum RESULT r)
 	else
 		msg = " [FAIL]";
 
-	if (llen < 64)
-		putcharn(' ', 64 - llen);
+	align_result(llen);
 	puts(msg);
 }