runtime: fix assembly syntax

Some assembler doesn't accept ULL suffix. In fact the suffix
is not really necessary. Drop it.

Change-Id: Ib64b2b566def0ebf47c7959b8423b08ae5fbbe52
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180217
Reviewed-by: Ian Lance Taylor <iant@golang.org>

libgo/runtime/go-context.S

diff --git a/libgo/runtime/go-context.S b/libgo/runtime/go-context.S
index 0cd2242..8beeebf 100644
--- a/libgo/runtime/go-context.S
+++ b/libgo/runtime/go-context.S
@@ -57,7 +57,7 @@
 	addq	%rcx, %rdx
 
 	// Align the SP, and push a dummy return address.
-	andq	$~0xfULL, %rdx
+	andq	$~0xf, %rdx
 	subq	$8, %rdx
 	movq	$0, (%rdx)