mm/damon/dbgfs: remove an unnecessary error message

mainline inclusion
from mainline-v5.16-rc5
commit 0bceffa2
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4RTX9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0bceffa236af401f5206feaf3538526cbc427209

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

When wrong scheme action is requested via the debugfs interface, DAMON
prints an error message.  Because the function returns error code, this
is not really needed.  Because the code path is triggered by the user
specified input, this can result in kernel log mistakenly being messy.
To avoid the case, this commit removes the message.

Link: https://lkml.kernel.org/r/20211201150440.1088-3-sj@kernel.org
Fixes: af122dd8 ("mm/damon/dbgfs: support DAMON-based Operation Schemes")
Signed-off-by: NSeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 0bceffa2)
Signed-off-by: NYue Zou <zouyue3@huawei.com>
Reviewed-by: Kefeng Wang<wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

mm/damon/dbgfs.c

@@ -210,10 +210,8 @@ static struct damos **str_to_schemes(const char *str, ssize_t len,
 				&wmarks.low, &parsed);
 		if (ret != 18)
 			break;
-		if (!damos_action_valid(action)) {
-			pr_err("wrong action %d\n", action);
+		if (!damos_action_valid(action))
 			goto fail;
-		}
 
 		pos += parsed;
 		scheme = damon_new_scheme(min_sz, max_sz, min_nr_a, max_nr_a,