sock_close() couldn't have been called with NULL inode since at least 2.1.early

... if not since 0.99 or so.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net/socket.c

@@ -1173,15 +1173,6 @@ static int sock_mmap(struct file *file, struct vm_area_struct *vma)
 
 static int sock_close(struct inode *inode, struct file *filp)
 {
-	/*
-	 *      It was possible the inode is NULL we were
-	 *      closing an unfinished socket.
-	 */
-
-	if (!inode) {
-		printk(KERN_DEBUG "sock_close: NULL inode\n");
-		return 0;
-	}
 	sock_release(SOCKET_I(inode));
 	return 0;
 }