new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index 62071d2..56662ae 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -889,7 +889,7 @@
 	unsigned long flags;
 	unsigned int data_buffer_length = 0;
 	unsigned long data_buffer_length_adjusted = 0;
-	struct inode *inode = file->f_dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	unsigned long *cpu_addr;
 	long timeout;
 	TW_New_Ioctl *tw_ioctl;