staging:rtl8192u: rename EEPROM_TxPwIndex_Ver - Style

Rename the constant EEPROM_TxPwIndex_Ver to
EEPROM_TX_PW_INDEX_VER, this clears the checkpatch issue with
CamelCase naming.

This is purely a coding style change which should have no impact
on runtime code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>