mm: memory-failure: cleanup try_to_split_thp_page()

Since commit 5d1fd5dc ("mm,hwpoison: introduce MF_MSG_UNSPLIT_THP"),
the action_result(,MF_MSG_UNSPLIT_THP,) called to show memory error event
in memory_failure(), so the pr_info() in try_to_split_thp_page() is only
needed in soft_offline_in_use_page().

Meanwhile this could also fix the unexpected prefix for "thp split failed"
due to commit 96f96763 ("mm: memory-failure: convert to pr_fmt()").

Link: https://lkml.kernel.org/r/20220809111813.139690-1-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -1524,20 +1524,18 @@ static int identify_page_state(unsigned long pfn, struct page *p,
 	return page_action(ps, p, pfn);
 }
 
-static int try_to_split_thp_page(struct page *page, const char *msg)
+static int try_to_split_thp_page(struct page *page)
 {
-	lock_page(page);
-	if (unlikely(split_huge_page(page))) {
-		unsigned long pfn = page_to_pfn(page);
+	int ret;
 
+	lock_page(page);
+	ret = split_huge_page(page);
 	unlock_page(page);
-		pr_info("%s: %#lx: thp split failed\n", msg, pfn);
+
+	if (unlikely(ret))
 		put_page(page);
-		return -EBUSY;
-	}
-	unlock_page(page);
 
-	return 0;
+	return ret;
 }
 
 static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn,
@@ -2079,7 +2077,7 @@ int memory_failure(unsigned long pfn, int flags)
 		 * page is a valid handlable page.
 		 */
 		SetPageHasHWPoisoned(hpage);
-		if (try_to_split_thp_page(p, "Memory Failure") < 0) {
+		if (try_to_split_thp_page(p) < 0) {
 			action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
 			res = -EBUSY;
 			goto unlock_mutex;
@@ -2505,8 +2503,11 @@ static int soft_offline_in_use_page(struct page *page)
 	struct page *hpage = compound_head(page);
 
 	if (!PageHuge(page) && PageTransHuge(hpage))
-		if (try_to_split_thp_page(page, "soft offline") < 0)
+		if (try_to_split_thp_page(page) < 0) {
+			pr_info("soft offline: %#lx: thp split failed\n",
+				page_to_pfn(page));
 			return -EBUSY;
+		}
 	return __soft_offline_page(page);
 }