lib / string_helpers: refactoring the test suite

This patch prepares test suite for a following update. It introduces
test_string_check_buf() helper which checks the result and dumps an error.

Signed-off-by: Andy Shevchenko <[e-mail]>
Cc: "John W . Linville" <[e-mail]>
Cc: Johannes Berg <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Joe Perches <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

lib/test-string_helpers.c

···
 #include <linux/string.h>
 #include <linux/string_helpers.h>
 
+static __init bool test_string_check_buf(const char *name, unsigned int flags,
+					 char *in, size_t p,
+					 char *out_real, size_t q_real,
+					 char *out_test, size_t q_test)
+{
+	if (q_real == q_test && !memcmp(out_test, out_real, q_test))
+		return true;
+
+	pr_warn("Test '%s' failed: flags = %u\n", name, flags);
+
+	print_hex_dump(KERN_WARNING, "Input: ", DUMP_PREFIX_NONE, 16, 1,
+		       in, p, true);
+	print_hex_dump(KERN_WARNING, "Expected: ", DUMP_PREFIX_NONE, 16, 1,
+		       out_test, q_test, true);
+	print_hex_dump(KERN_WARNING, "Got: ", DUMP_PREFIX_NONE, 16, 1,
+		       out_real, q_real, true);
+
+	return false;
+}
+
 struct test_string {
 	const char *in;
 	const char *out;
···
 	},
 };
 
-static void __init test_string_unescape(unsigned int flags, bool inplace)
+static void __init test_string_unescape(const char *name, unsigned int flags,
+					bool inplace)
 {
 	char in[256];
 	char out_test[256];
···
 		q_real = string_unescape(in, out_real, q_real, flags);
 	}
 
-	if (q_real != q_test || memcmp(out_test, out_real, q_test)) {
-		pr_warn("Test failed: flags = %u\n", flags);
-		print_hex_dump(KERN_WARNING, "Input: ",
-			       DUMP_PREFIX_NONE, 16, 1, in, p - 1, true);
-		print_hex_dump(KERN_WARNING, "Expected: ",
-			       DUMP_PREFIX_NONE, 16, 1, out_test, q_test, true);
-		print_hex_dump(KERN_WARNING, "Got: ",
-			       DUMP_PREFIX_NONE, 16, 1, out_real, q_real, true);
-	}
+	test_string_check_buf(name, flags, in, p - 1, out_real, q_real,
+			      out_test, q_test);
 }
 
 static int __init test_string_helpers_init(void)
···
 
 	pr_info("Running tests...\n");
 	for (i = 0; i < UNESCAPE_ANY + 1; i++)
-		test_string_unescape(i, false);
-	test_string_unescape(get_random_int() % (UNESCAPE_ANY + 1), true);
+		test_string_unescape("unescape", i, false);
+	test_string_unescape("unescape inplace",
+			     get_random_int() % (UNESCAPE_ANY + 1), true);
 
 	return -EINVAL;
 }