new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 52a2f058..c845bdb 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -757,7 +757,7 @@
 	dma_addr_t dma_handle;
 	int request_id = 0;
 	TW_Ioctl_Driver_Command driver_command;
-	struct inode *inode = file->f_dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	TW_Ioctl_Buf_Apache *tw_ioctl;
 	TW_Command_Full *full_command_packet;
 	TW_Device_Extension *tw_dev = twl_device_extension_list[iminor(inode)];