new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/mips/kernel/vpe.c

@@ -1149,7 +1149,7 @@ static ssize_t vpe_write(struct file *file, const char __user * buffer,
 	size_t ret = count;
 	struct vpe *v;
 
-	if (iminor(file->f_path.dentry->d_inode) != minor)
+	if (iminor(file_inode(file)) != minor)
 		return -ENODEV;
 
 	v = get_vpe(tclimit);