drivers/base: Convert dev->sem to mutex

The semaphore is semantically a mutex. Convert it to a real mutex and
fix up a few places where code was relying on semaphore.h to be included
by device.h, as well as the users of the trylock function, as that value
is now reversed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index bc72d6e..13343e8 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -40,6 +40,7 @@
 #include <linux/mutex.h>
 #include <linux/radix-tree.h>
 #include <linux/timer.h>
+#include <linux/semaphore.h>
 #include <linux/workqueue.h>
 
 #include <linux/mlx4/device.h>