staging: wlan-ng: renames hfa384x_InfFrame to avoid camelcase

Renames hfa384x_InfFrame to hfa384x_inf_frame in order to fix a
checkpatch error caused by camelcase.

Signed-off-by: Juliana Rodrigues <juliana.orod@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>