misc/ios: fix wording for command line instructions
misc/ios: fix wording for command line instructions

A typo was made, which I noticed while looking through the recent master
commits.

Change-Id: Ieed5d6664a1f3ff5892d59abf194963b44ef0e55
Reviewed-on: https://go-review.googlesource.com/c/go/+/280454
Trust: Daniel Martí <29bf28b42a938ace12a5819da4ed4ba03d82f315@mvdan.cc>
Reviewed-by: Cherry Zhang <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>

CAFxX/go,cloudflare/go,golang/go,CAFxX/go,golang/go,cloudflare/go,nawawi/go,cloudflare/go,nawawi/go,nawawi/go,CAFxX/go,cloudflare/go,cloudflare/go,golang/go,golang/go,cloudflare/go,CAFxX/go,nawawi/go,cloudflare/go,CAFxX/go,golang/go,CAFxX/go,CAFxX/go,golang/go,golang/go,CAFxX/go,nawawi/go,golang/go,nawawi/go,nawawi/go,cloudflare/go,nawawi/go