Staging: rtl8192u: r8180_93cx6.c: Fix space around '<<'.

Fix the check as per Linux kernel style for use of spaces.
Issue found by checkpatch.pl

CHECK:spaces preffered around that '<<'

Signed-off-by: Sanjana Sanikommu <sanjana99reddy99@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>