rtl8xxxu: tx rate reported before set

Move the dev_info call that attempts to show the rate used before it is set.

Signed-off-by: Barry Day <briselec@gmail.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Barry Day <briselec@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>