staging: r8188eu: Add blank line after declarations

This patch adds a blank line after the variable declarations,
it should remove a checkpatch.pl warning and improve readability.

checkpatch output:

WARNING: Missing a blank line after declarations

Signed-off-by: Rommel Rodriguez Perez <alrodperez@gmail.com>
Link: https://lore.kernel.org/r/YqALs/7VkGsYUngw@debianmain.debian.pc.org


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