Remove incorrect TODO(fork).

The OR seems to be correct. %r9d previously contains 1 for a non-Intel
CPU. The next line isolates the XOP bit but *also* preserves that 1.
This figures in later in in line 121 to avoid tagging as Intel. (Most
codepaths in the AMD-specific branch go straight to .Lgeneric, but some
go to .Lintel. This probably could be done more clearly as there's some
complicated code that's subtly different...)

Change-Id: Ie7b9566074498333f26416e46478e4f4df68194f
Reviewed-on: https://boringssl-review.googlesource.com/5433
Reviewed-by: Adam Langley <agl@google.com>

crypto/cpu-x86_64-asm.pl

@@ -70,7 +70,6 @@ OPENSSL_ia32_cpuid:
 	mov	\$0x80000001,%eax
 	cpuid
 	# Returns feature bits in ECX. See page 20 of [1].
-	# TODO(fork): I think this should be a MOV.
 	or	%ecx,%r9d
 	and	\$0x00000801,%r9d	# isolate AMD XOP bit, 1<<11