md/raid1: rename print_msg with r1bio_existed

mainline inclusion
from mainline-v5.14-rc1
commit 9b8ae7b9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I587H6
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9b8ae7b938235229ccb112c4e887ff1bcc232836

-------------------------------

The caller of raid1_read_request could pass NULL or a valid pointer for
"struct r1bio *r1_bio", so it actually means whether r1_bio is existed
or not.
Signed-off-by: NGuoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: NSong Liu <song@kernel.org>
Signed-off-by: NZhang Wensheng <zhangwensheng5@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/md/raid1.c

@@ -1210,7 +1210,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
 	int max_sectors;
 	int rdisk;
-	bool print_msg = !!r1_bio;
+	bool r1bio_existed = !!r1_bio;
 	char b[BDEVNAME_SIZE];
 
 	/*
@@ -1220,7 +1220,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	 */
 	gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
 
-	if (print_msg) {
+	if (r1bio_existed) {
 		/* Need to get the block device name carefully */
 		struct md_rdev *rdev;
 		rcu_read_lock();
@@ -1252,7 +1252,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 
 	if (rdisk < 0) {
 		/* couldn't find anywhere to read from */
-		if (print_msg) {
+		if (r1bio_existed) {
 			pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
 					    mdname(mddev),
 					    b,
@@ -1263,7 +1263,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	}
 	mirror = conf->mirrors + rdisk;
 
-	if (print_msg)
+	if (r1bio_existed)
 		pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %s\n",
 				    mdname(mddev),
 				    (unsigned long long)r1_bio->sector,