thermal: sysfs: Use str_enabled_disabled() helper in mode_show()

Replace hard-coded strings with the str_enabled_disabled() helper.

This unifies the output and helps the linker with deduplication, which
may result in a smaller binary.

Signed-off-by: Thorsten Blum <[e-mail]>
[ rjw: Subject and changelog tweaks ]
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/thermal/thermal_sysfs.c

···
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/string_choices.h>
 #include <linux/jiffies.h>
 
 #include "thermal_core.h"
···
 
 	guard(thermal_zone)(tz);
 
-	if (tz->mode == THERMAL_DEVICE_ENABLED)
-		return sysfs_emit(buf, "enabled\n");
-
-	return sysfs_emit(buf, "disabled\n");
+	return sysfs_emit(buf, "%s\n",
+		str_enabled_disabled(tz->mode == THERMAL_DEVICE_ENABLED));
 }
 
 static ssize_t