lib/test-string_helpers: replace UNESCAPE_ANY by UNESCAPE_ALL_MASK

When we get a random number to generate a flag in the valid range of
UNESCAPE flags, use UNESCAPE_ALL_MASK, It's more correct and prevents from
missed updates of the test coverage in the future if any.

Link: https://lkml.kernel.org/r/20230327142604.48213-1-andriy.shevchenko@linux.intel.comSigned-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/test-string_helpers.c

@@ -587,7 +587,7 @@ static int __init test_string_helpers_init(void)
 	for (i = 0; i < UNESCAPE_ALL_MASK + 1; i++)
 		test_string_unescape("unescape", i, false);
 	test_string_unescape("unescape inplace",
-			     get_random_u32_below(UNESCAPE_ANY + 1), true);
+			     get_random_u32_below(UNESCAPE_ALL_MASK + 1), true);
 
 	/* Without dictionary */
 	for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)