rtlwifi: rtl8188ee: Fix loop that ends early

In routine _rtl8188e_read_power_value_fromprom(), there are loops initializing
index_cck_base and index_bw40_base from the PROM. As the result of a typo, the
second loop is ended one element too soon.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>