ibmvmc: don't open-code file_inode()

badly, at that...
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/misc/ibmvmc.c

@@ -1039,6 +1039,7 @@ static unsigned int ibmvmc_poll(struct file *file, poll_table *wait)
 static ssize_t ibmvmc_write(struct file *file, const char *buffer,
 			    size_t count, loff_t *ppos)
 {
+	struct inode *inode;
 	struct ibmvmc_buffer *vmc_buffer;
 	struct ibmvmc_file_session *session;
 	struct crq_server_adapter *adapter;
@@ -1122,8 +1123,9 @@ static ssize_t ibmvmc_write(struct file *file, const char *buffer,
 	if (p == buffer)
 		goto out;
 
-	file->f_path.dentry->d_inode->i_mtime = current_time(file_inode(file));
-	mark_inode_dirty(file->f_path.dentry->d_inode);
+	inode = file_inode(file);
+	inode->i_mtime = current_time(inode);
+	mark_inode_dirty(inode);
 
 	dev_dbg(adapter->dev, "write: file = 0x%lx, count = 0x%lx\n",
 		(unsigned long)file, (unsigned long)count);