rtlwifi: Remove double check for cnt_after_linked

rtl_lps_enter does two successive check for cnt_after_linked
to make sure some time has elapsed after linked. The second
check isn't necessary, because if cnt_after_linked is bigger
than 5, it is bigger than 2 of course!

This patch remove the second check code.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>