[S390] 3215/3270 console: remove wrong comment

When converting these two drivers from bootmem to slab allocations I
forgot to remove two comments which state that this wouldn't be
possible.
So remove them now since this caused confusion already.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/con3215.c

@@ -857,7 +857,6 @@ static struct console con3215 = {
 
 /*
  * 3215 console initialization code called from console_init().
- * NOTE: This is called before kmalloc is available.
  */
 static int __init con3215_init(void)
 {

drivers/s390/char/con3270.c

@@ -572,7 +572,6 @@ static struct console con3270 = {
 
 /*
  * 3270 console initialization code called from console_init().
- * NOTE: This is called before kmalloc is available.
  */
 static int __init
 con3270_init(void)