drivers/char/vt_ioctl.c: fix VT_OPENQRY error value

When all VT's are in use, VT_OPENQRY casts -1 to unsigned char before
returning it to userspace as an int.  VT255 is not the next available
console.
Signed-off-by: Graham Gower <graham.gower@gmail.com>
Cc: Greg KH <greg@kroah.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/vt_ioctl.c

@@ -503,6 +503,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
 	struct kbd_struct * kbd;
 	unsigned int console;
 	unsigned char ucval;
+	unsigned int uival;
 	void __user *up = (void __user *)arg;
 	int i, perm;
 	int ret = 0;
@@ -657,7 +658,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
 		break;
 
 	case KDGETMODE:
-		ucval = vc->vc_mode;
+		uival = vc->vc_mode;
 		goto setint;
 
 	case KDMAPDISP:
@@ -695,7 +696,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
 		break;
 
 	case KDGKBMODE:
-		ucval = ((kbd->kbdmode == VC_RAW) ? K_RAW :
+		uival = ((kbd->kbdmode == VC_RAW) ? K_RAW :
 				 (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
 				 (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
 				 K_XLATE);
@@ -717,9 +718,9 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
 		break;
 
 	case KDGKBMETA:
-		ucval = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
+		uival = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
 	setint:
-		ret = put_user(ucval, (int __user *)arg);
+		ret = put_user(uival, (int __user *)arg);
 		break;
 
 	case KDGETKEYCODE:
@@ -949,7 +950,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
 		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 			if (! VT_IS_IN_USE(i))
 				break;
-		ucval = i < MAX_NR_CONSOLES ? (i+1) : -1;
+		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 		goto setint;		 
 
 	/*