sparc64: Fix ITLB handler of null page

1)Use kvmap_itlb_longpath instead of kvmap_dtlb_longpath.

2)Handle page #0 only, don't handle page #1: bleu -> blu

 (KERNBASE is 0x400000, so #1 does not exist too. But everything
  is possible in the future. Fix to not to have problems later.)

3)Remove unused kvmap_itlb_nonlinear.
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/ktlb.S

@@ -25,11 +25,10 @@ kvmap_itlb:
 	 */
 kvmap_itlb_4v:
 
-kvmap_itlb_nonlinear:
 	/* Catch kernel NULL pointer calls.  */
 	sethi		%hi(PAGE_SIZE), %g5
 	cmp		%g4, %g5
-	bleu,pn		%xcc, kvmap_dtlb_longpath
+	blu,pn		%xcc, kvmap_itlb_longpath
 	 nop
 
 	KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_itlb_load)