[forwardport] fix(netxlite): remove android-specific errno (#586) (#587)

This commit forward ports 74947dbbd12266c12a38fad51a70fc78a21720fd from
the `release/3.11` branch to `master`. Here's the original commit message:

- - -

Android is also Linux. The Android build fails because both
errno_linux.go and errno_android.go are compiled.

There's no difference between the files except into a comment
that mentions "linux" or "android".

Therefore, it's safe to remove the android-specific file
and just keep and use the linux-specific one.

Part of https://github.com/ooni/probe/issues/1863, where we're
forward porting ooni/go patches to go1.17.

I'm still trying to figure out whether I can build oonimkall
using the forward ported patches and this error prevents me
from building, because the build fails.

"やれやれだぜ"

Note that this patch WILL need to be forward ported to master.

This bug was previosuly reported to me by @hellais.

Because I did run `go generate ./internal/netxlite/...` we also
get for free updated certificates, which is OK.

internal/netxlite/errno_linux.go

@@ -1,5 +1,5 @@
 // Code generated by go generate; DO NOT EDIT.
-// Generated: 2021-10-20 14:12:55.309355 +0200 CEST m=+0.464820460
+// Generated: 2021-11-10 12:32:22.795026799 +0100 CET m=+2.554985925
 
 package netxlite