staging: rtl8723bs: Add spaces around '='

Use one space around (on each side of) '=' operator

Signed-off-by: Harsha Sharma <harshasharmaiitr@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>