staging: rtl8192e: Rename variable InitialGainHandler

Rename variable InitialGainHandler to init_gain_handler to avoid
CamelCase which is not accepted by checkpatch.

Signed-off-by: Yogesh Hegde <yogi.kernel@gmail.com>
Link: https://lore.kernel.org/r/a2f37a6cb962e9775978ae5f4fde958b74806a4e.1687183827.git.yogi.kernel@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>