staging: silicom: fix trailing whitespace in libbp_sd.h

Fixes checkpatch.pl trailing whitespace errors.

Signed-off-by: Jade Bilkey <herself@thefumon.com>
Reviewed-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>