copy_signal() cleanup: kill taskstats_tgid_init() and acct_init_pacct()

Kill unused functions taskstats_tgid_init() and acct_init_pacct() because
we don't use them anywhere after using kmem_cache_zalloc() in
copy_signal().

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --cc include/linux/acct.h
Simple merge

diff --cc include/linux/taskstats_kern.h
Simple merge

diff --cc kernel/acct.c
Simple merge