scsi: esas2r: Replace semaphore fm_api_semaphore with mutex

The semaphore 'fm_api_semaphore' is used as a simple mutex, so it should
be written as one. Semaphores are going away in the future.

Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/esas2r/esas2r.h

@@ -945,7 +945,7 @@ struct esas2r_adapter {
 	struct list_head vrq_mds_head;
 	struct esas2r_mem_desc *vrq_mds;
 	int num_vrqs;
-	struct semaphore fm_api_semaphore;
+	struct mutex fm_api_mutex;
 	struct semaphore fs_api_semaphore;
 	struct semaphore nvram_semaphore;
 	struct atto_ioctl *local_atto_ioctl;