hwmon: (f75375s) fix pwm mode setting

Spotted by the Coverity checker. (Thanks Adrian Bunk)

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
index 13a0413..59a3470 100644
--- a/drivers/hwmon/f75375s.c
+++ b/drivers/hwmon/f75375s.c
@@ -323,7 +323,7 @@
 	int val = simple_strtoul(buf, NULL, 10);
 	u8 conf = 0;
 
-	if (val != 0 || val != 1 || data->kind == f75373)
+	if (!(val == 0 || val == 1) || data->kind == f75373)
 		return -EINVAL;
 
 	mutex_lock(&data->update_lock);