staging: rtl8192e: adjust size of trsw_gain_X for new RF90_PATH_MAX

staging: rtl8192e: adjust size of trsw_gain_X for new RF90_PATH_MAX

The array trsw_gain_X in struct phy_sts_ofdm_819xpci is always accessed by
indices in the range i = 0; i < RF90_PATH_MAX. A previous patch changed the
value of RF90_PATH_MAX from 4 to 2, so we can reduce the size of
trsw_gain_X to 2. Use RF90_PATH_MAX instead of a hard-coded size.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20240831100809.29173-4-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>