selftests/damon/huge_count_read_write: remove unnecessary debugging message

The program prints expected errors from write/read of the files with
invalid huge count, for only debugging purpose.  It is only making the
output noisy.  Remove those.

Link: https://lkml.kernel.org/r/20241028233058.283381-3-sj@kernel.org
Fixes: b4a002889d ("selftests/damon: test debugfs file reads/writes with huge count")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Andrew Paniakin <apanyaki@amazon.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/damon/huge_count_read_write.c

@@ -28,9 +28,7 @@ void write_read_with_huge_count(char *file)
 	}
 
 	write(filedesc, "", 0xfffffffful);
-	perror("after write: ");
 	ret = read(filedesc, buf, 0xfffffffful);
-	perror("after read: ");
 	close(filedesc);
 }