staging: rtl8712: Merge memcpy + be16_to_cpus to get_unaligned_be16

Merge the combo of memcpy and be16_to_cpus.
Use get_unaligned_be16 instead.
This simplifies the code.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20190719070921.27749-1-hslester96@gmail.com


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