selftests/thermal: remove duplicate newlines in perror calls

perror() automatically appends a newline character, so the explicit '\n'
in the format strings is redundant and results in duplicate newlines in
the output.

Remove the redundant '\n' characters from perror() calls in
workload_hint_test.c to fix the formatting.

Link: https://lkml.kernel.org/r/F482FB1EC020000C+20250710134751.306096-1-wangyuli@uniontech.com
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Cc: Guan Wentao <guanwentao@uniontech.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: WangYuli

tools/testing/selftests/thermal/intel/workload_hint/workload_hint_test.c

@@ -32,12 +32,12 @@ void workload_hint_exit(int signum)
 
 	fd = open(WORKLOAD_ENABLE_ATTRIBUTE, O_RDWR);
 	if (fd < 0) {
-		perror("Unable to open workload type feature enable file\n");
+		perror("Unable to open workload type feature enable file");
 		exit(1);
 	}
 
 	if (write(fd, "0\n", 2) < 0) {
-		perror("Can't disable workload hints\n");
+		perror("Can't disable workload hints");
 		exit(1);
 	}
 
@@ -70,12 +70,12 @@ int main(int argc, char **argv)
 		sprintf(delay_str, "%s\n", argv[1]);
 		fd = open(WORKLOAD_NOTIFICATION_DELAY_ATTRIBUTE, O_RDWR);
 		if (fd < 0) {
-			perror("Unable to open workload notification delay\n");
+			perror("Unable to open workload notification delay");
 			exit(1);
 		}
 
 		if (write(fd, delay_str, strlen(delay_str)) < 0) {
-			perror("Can't set delay\n");
+			perror("Can't set delay");
 			exit(1);
 		}
 
@@ -92,12 +92,12 @@ int main(int argc, char **argv)
 	/* Enable feature via sysfs knob */
 	fd = open(WORKLOAD_ENABLE_ATTRIBUTE, O_RDWR);
 	if (fd < 0) {
-		perror("Unable to open workload type feature enable file\n");
+		perror("Unable to open workload type feature enable file");
 		exit(1);
 	}
 
 	if (write(fd, "1\n", 2) < 0) {
-		perror("Can't enable workload hints\n");
+		perror("Can't enable workload hints");
 		exit(1);
 	}
 
@@ -108,7 +108,7 @@ int main(int argc, char **argv)
 	while (1) {
 		fd = open(WORKLOAD_TYPE_INDEX_ATTRIBUTE, O_RDONLY);
 		if (fd < 0) {
-			perror("Unable to open workload type file\n");
+			perror("Unable to open workload type file");
 			exit(1);
 		}