tty: vt, remove reduntant check

MAX_NR_CONSOLES and MAX_NR_USER_CONSOLES are both 63 since they were
introduced in 1.1.54. And since vc_allocate does:

if (currcons >= MAX_NR_CONSOLES)
return -ENXIO;

if (!vc_cons[currcons].d) {
if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
return -EPERM;
}

the second check is pointless. Remove both the check and the macro
MAX_NR_USER_CONSOLES.

Signed-off-by: Jiri Slaby <[e-mail]>
Reported-by: Fugang Duan <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/vt/vt.c

···
 	    struct vc_data *vc;
 	    struct vt_notifier_param param;
 
-	    /* prevent users from taking too much memory */
-	    if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
-	      return -EPERM;
-
 	    /* due to the granularity of kmalloc, we waste some memory here */
 	    /* the alloc is done in two steps, to optimize the common situation
 	       of a 25x80 console (structsize=216, screenbuf_size=4000) */

include/uapi/linux/vt.h

···
  */
 #define MIN_NR_CONSOLES 1       /* must be at least 1 */
 #define MAX_NR_CONSOLES	63	/* serial lines start at 64 */
-#define MAX_NR_USER_CONSOLES 63	/* must be root to allocate above this */
 		/* Note: the ioctl VT_GETSTATE does not work for
 		   consoles 16 and higher (since it returns a short) */