rtlwifi: rtl8192cu: Fix duplicate if test

commit 10d0b9030a3f86e1e26c710c7580524d7787d688 upstream.

A typo causes routine rtl92cu_phy_rf6052_set_cck_txpower() to test the
same condition twice. The problem was found using cppcheck-1.49, and the
proper fix was verified against the pre-mac80211 version of the code.

This patch was originally included as commit 1288aa4e, but was accidentally
reverted in a later patch.

Reported-by: David Binderman <dcb314@hotmail.com> [original report]
Reported-by: Andrea Morello <andrea.merello@gmail.com> [report of accidental reversion]
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>