fs/kernfs: remove the double check of dentry->inode

In both kernfs_node_from_dentry() and in
kernfs_dentry_node(), we will check the dentry->inode
is NULL or not, which is superfluous.

So remove the check in kernfs_node_from_dentry().
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hui Su <sh_def@163.com>
Link: https://lore.kernel.org/r/20201113132143.GA119541@rlkSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/kernfs/dir.c

@@ -604,8 +604,7 @@ const struct dentry_operations kernfs_dops = {
  */
 struct kernfs_node *kernfs_node_from_dentry(struct dentry *dentry)
 {
-	if (dentry->d_sb->s_op == &kernfs_sops &&
-	    !d_really_is_negative(dentry))
+	if (dentry->d_sb->s_op == &kernfs_sops)
 		return kernfs_dentry_node(dentry);
 	return NULL;
 }