rtl8192u: fix whitespace around relational operators in r8192U_core.c

This patch fixes whitespace around relational operators
following the kernel coding style conventions.
It corrects the following checkpatch errors:
ERROR: spaces required around that '=='
ERROR: spaces required around that '!'
ERROR: spaces required around that '<='
ERROR: spaces required around that '>='
ERROR: spaces required around that '<'
ERROR: spaces required around that '>'

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>