Don't init pgrp and __session in INIT_SIGNALS

Remove initialization of pgrp and __session in INIT_SIGNALS, as these are
later set by the call to __set_special_pids() in init/main.c by the patch:

	explicitly-set-pgid-and-sid-of-init-process.patch
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/init_task.h

@@ -65,9 +65,9 @@
 	.posix_timers	 = LIST_HEAD_INIT(sig.posix_timers),		\
 	.cpu_timers	= INIT_CPU_TIMERS(sig.cpu_timers),		\
 	.rlim		= INIT_RLIMITS,					\
-	.pgrp		= 1,						\
+	.pgrp		= 0,						\
 	.tty_old_pgrp   = NULL,						\
-	{ .__session      = 1},						\
+	{ .__session      = 0},						\
 }
 
 extern struct nsproxy init_nsproxy;