Staging: lustre: Fix Space Prohibition before '++' in conrpc.c

This patch fixes the following checkpatch.pl error in conrpc.c-
ERROR: space prohibited before that '++'

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>