fs/9p: fix indentation and Add missing a blank line after declaration

Warning found by checkpatch.pl

Link: http://lkml.kernel.org/r/20210930220420.44150-1-sohaib.amhmd@gmail.com
Signed-off-by: Sohaib Mohamed <sohaib.amhmd@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>