net: test: Fix printf format specifier in skb_segment kunit test

KUNIT_FAIL() accepts a printf-style format string, but previously did
not let gcc validate it with the __printf() attribute. The use of %lld
for the result of PTR_ERR() is not correct.

Instead, use %pe and pass the actual error pointer. printk() will format
it correctly (and give a symbolic name rather than a number if
available, which should make the output more readable, too).

Fixes: b3098d32 ("net: add skb_segment kunit test")
Signed-off-by: David Gow <davidgow@google.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

net/core/gso_test.c

@@ -225,7 +225,7 @@ static void gso_test_func(struct kunit *test)
 
 	segs = skb_segment(skb, features);
 	if (IS_ERR(segs)) {
-		KUNIT_FAIL(test, "segs error %lld", PTR_ERR(segs));
+		KUNIT_FAIL(test, "segs error %pe", segs);
 		goto free_gso_skb;
 	} else if (!segs) {
 		KUNIT_FAIL(test, "no segments");