staging: rts5208: ensure braces on all arms of if stmt

Added braces on if arm of if statement where else arm already needs
braces as suggested for clarity in Documentation/CodingStyle (several)

Signed-off-by: Nicholas Sim <nicholassimws@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>