mutex: make 0/1 FIO_MUTEX_LOCKED and FIO_MUTEX_UNLOCKED

Makes the API look cleaner.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/diskutil.c b/diskutil.c
index f51d07b..a3a5b4d 100644
--- a/diskutil.c
+++ b/diskutil.c
@@ -290,7 +290,7 @@
 	du->minor = mindev;
 	INIT_FLIST_HEAD(&du->slavelist);
 	INIT_FLIST_HEAD(&du->slaves);
-	du->lock = fio_mutex_init(1);
+	du->lock = fio_mutex_init(FIO_MUTEX_UNLOCKED);
 	du->users = 0;
 
 	fio_mutex_down(disk_util_mutex);
@@ -624,5 +624,5 @@
 
 void setup_disk_util(void)
 {
-	disk_util_mutex = fio_mutex_init(1);
+	disk_util_mutex = fio_mutex_init(FIO_MUTEX_UNLOCKED);
 }