fs3270: Correct error returns

Drop the kernel lock further and also correct cases where we set rc to an
error code, and then return 0
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/s390/char/fs3270.c

@@ -418,23 +418,22 @@ fs3270_open(struct inode *inode, struct file *filp)
 {
 	struct fs3270 *fp;
 	struct idal_buffer *ib;
-	int minor, rc;
+	int minor, rc = 0;
 
 	if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 		return -ENODEV;
-	lock_kernel();
 	minor = iminor(filp->f_path.dentry->d_inode);
 	/* Check for minor 0 multiplexer. */
 	if (minor == 0) {
 		struct tty_struct *tty = get_current_tty();
 		if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 			tty_kref_put(tty);
-			rc = -ENODEV;
-			goto out;
+			return -ENODEV;
 		}
 		minor = tty->index + RAW3270_FIRSTMINOR;
 		tty_kref_put(tty);
 	}
+	lock_kernel();
 	/* Check if some other program is already using fullscreen mode. */
 	fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 	if (!IS_ERR(fp)) {
@@ -476,7 +475,7 @@ fs3270_open(struct inode *inode, struct file *filp)
 	filp->private_data = fp;
 out:
 	unlock_kernel();
-	return 0;
+	return rc;
 }
 
 /*