x86/x86asm: fix function name in comment

Change-Id: Ie70c842161c96948098082d3c0ff1b026bcfd8de
Reviewed-on: https://go-review.googlesource.com/c/arch/+/579198
Reviewed-by: qiu laidongfeng2 <2645477756@qq.com>
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Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Run-TryBot: shuang cui <imcusg@gmail.com>

x86/x86asm/ext_test.go

@@ -653,7 +653,7 @@ func enum8bit(try func([]byte)) {
 	}
 }
 
-// enum8bit generates all possible 2-byte sequences, followed by distinctive padding.
+// enum16bit generates all possible 2-byte sequences, followed by distinctive padding.
 func enum16bit(try func([]byte)) {
 	for i := 0; i < 1<<16; i++ {
 		try([]byte{byte(i), byte(i >> 8), 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88})