doc: fix mistake in NetBSD notes

It's 32-bit binaries that fail for reasons unknown on 64-bit kernels.

Change-Id: Ib410af0491160e3ed8d32118966142516123db2c
Reviewed-on: https://go-review.googlesource.com/82655Reviewed-by: Andrew Bonventre <andybons@golang.org>

doc/go1.10.html

@@ -78,8 +78,8 @@ support for FreeBSD 9.3 has been removed.
 <p id="netbsd">
 Go now runs on NetBSD again, but requires the unreleased NetBSD 8.
 Only <code>GOARCH=amd64</code> running on NetBSD amd64 and <code>GOARCH=386</code>
-running on NetBSD i386 are known to work. 64-bit Go binaries are known to
-fail on 32-bit NetBSD kernels. <code>GOARCH=arm</code> is untested.
+running on NetBSD i386 are known to work. 32-bit Go binaries are known to
+fail on 64-bit NetBSD kernels. <code>GOARCH=arm</code> is untested.
 </p>
 
 <p id="openbsd">