staging: lustre: socklnd: Remove unnecessary return brackets

Remove unnecessary brackets from return statements in socklnd.c,
socklnd.h, socklnd_cb.c and socklnd_lib-linux.c to meet
kernel coding style.

Signed-off-by: Masaru Nomura <massa.nomura@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>