6l: drop confusing comment

R=ken2
CC=golang-dev
https://golang.org/cl/1693047
diff --git a/src/cmd/6l/optab.c b/src/cmd/6l/optab.c
index c8aa0b5..c729f0e 100644
--- a/src/cmd/6l/optab.c
+++ b/src/cmd/6l/optab.c
@@ -792,7 +792,7 @@
 	{ AMOVLPD,	yxmov,	Pe, 0x12,0x13 },
 	{ AMOVLPS,	yxmov,	Pm, 0x12,0x13 },
 	{ AMOVLQSX,	yml_rl,	Pw, 0x63 },
-	{ AMOVLQZX,	yml_rl,	Px, 0x8b },	/* not 0x63 - MOVL (0x8b) is more widely understood and has same effect */
+	{ AMOVLQZX,	yml_rl,	Px, 0x8b },
 	{ AMOVMSKPD,	yxrrl,	Pq, 0x50 },
 	{ AMOVMSKPS,	yxrrl,	Pm, 0x50 },
 	{ AMOVNTO,	yxr_ml,	Pe, 0xe7 },