init/main.c: log arguments and environment passed to init

Extend logging in `run_init_process` to also show the arguments and
environment that we are passing to init.

Link: http://lkml.kernel.org/r/20191212180023.24339-2-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>