Ruby cvs 2.6.12 did not compile

[Helge H. <hel...@ai...>]

Checked out ruby cvs, saw that it was 2.6.12, copied it over a 2.6.12
source tree, got this upon compile:

  CHK     include/linux/version.h
make[1]: `arch/x86_64/kernel/asm-offsets.s' is up to date.
  CHK     include/linux/compile.h
  CHK     usr/initramfs_list
  CC      drivers/char/decvte.o
drivers/char/decvte.c: In function `set_mode':
drivers/char/decvte.c:514: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:516: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c:547: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:549: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c:568: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:570: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c:596: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:598: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c: In function `vte_ris':
drivers/char/decvte.c:999: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:1000: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c:1001: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c:1002: error: incompatible type for argument 1 of 
`clr_kbd_mode'
drivers/char/decvte.c: In function `terminal_emulation':
drivers/char/decvte.c:1122: error: incompatible type for argument 1 of 
`get_kbd_mode'
drivers/char/decvte.c:1296: error: incompatible type for argument 1 of 
`set_kbd_mode'
drivers/char/decvte.c:1300: error: incompatible type for argument 1 of 
`clr_kbd_mode'
make[2]: *** [drivers/char/decvte.o] Error 1
make[1]: *** [drivers/char] Error 2
make: *** [drivers] Error 2