x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAX

Impact: cleanup

Rename TASK_SIZE64 to TASK_SIZE_MAX, and provide the
define on 32-bit too. (mapped to TASK_SIZE)

This allows 32-bit code to make use of the (former-) TASK_SIZE64
symbol as well, in a clean way.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index d2f7cd5..fb2159a 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -268,7 +268,7 @@
 	if (test_tsk_thread_flag(task, TIF_IA32))
 		return IA32_PAGE_OFFSET - 3;
 #endif
-	return TASK_SIZE64 - 7;
+	return TASK_SIZE_MAX - 7;
 }
 
 #endif	/* CONFIG_X86_32 */