staging: r8188eu: Fixed two whitespace coding style issues

Replaced spaces with tabs as per checkpatch.pl

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Chang Yu <marcus.yu.56@gmail.com>
Link: https://lore.kernel.org/r/68cb57799d9139740f94eed9080e2d08c522e74c.1655872968.git.marcus.yu.56@gmail.com


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