memsw: remove noswapaccount kernel parameter

The noswapaccount parameter has been deprecated since 2.6.38 without any
complaints from users so we can remove it.  swapaccount=0|1 can be used
instead.

As we are removing the parameter we can also clean up swapaccount because
it doesn't have to accept an empty string anymore (to match noswapaccount)
and so we can push = into __setup macro rather than checking "=1" resp.
"=0" strings

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/kernel-parameters.txt

@@ -1777,9 +1777,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	nosoftlockup	[KNL] Disable the soft-lockup detector.
 
-	noswapaccount	[KNL] Disable accounting of swap in memory resource
-			controller. (See Documentation/cgroups/memory.txt)
-
 	nosync		[HW,M68K] Disables sync negotiation for all devices.
 
 	notsc		[BUGS=X86-32] Disable Time Stamp Counter

mm/memcontrol.c

@@ -5169,19 +5169,12 @@ struct cgroup_subsys mem_cgroup_subsys = {
 static int __init enable_swap_account(char *s)
 {
 	/* consider enabled if no parameter or 1 is given */
-	if (!(*s) || !strcmp(s, "=1"))
+	if (!strcmp(s, "1"))
 		really_do_swap_account = 1;
-	else if (!strcmp(s, "=0"))
+	else if (!strcmp(s, "0"))
 		really_do_swap_account = 0;
 	return 1;
 }
-__setup("swapaccount", enable_swap_account);
+__setup("swapaccount=", enable_swap_account);
 
-static int __init disable_swap_account(char *s)
-{
-	printk_once("noswapaccount is deprecated and will be removed in 2.6.40. Use swapaccount=0 instead\n");
-	enable_swap_account("=0");
-	return 1;
-}
-__setup("noswapaccount", disable_swap_account);
 #endif