kernel/params.c: improve STANDARD_PARAM_DEF readability

Align the parameters passed to STANDARD_PARAM_DEF for clarity.

Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymionSigned-off-by: Jean Delvare <jdelvare@suse.de>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>