staging: rtl8188eu: rename variables to avoid mixed case

Rename local variables to avoid mixed case.

max_AMPDU_len -> max_ampdu_len
min_MPDU_spacing -> min_mpdu_spacing

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20191015154535.27979-1-straube.linux@gmail.com


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