xen/tmem: Remove the usage of 'noselfshrink' and use 'tmem.selfshrink' bool instead.

As the 'tmem' driver is the one that actually sets whether
it will use it or not so might as well make tmem responsible
for this knob.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/Kconfig

@@ -22,7 +22,7 @@ config XEN_SELFBALLOONING
 	  ballooning is disabled by default but can be enabled with the
 	  'selfballooning' kernel boot parameter.  If FRONTSWAP is configured,
 	  frontswap-selfshrinking is enabled by default but can be disabled
-	  with the 'noselfshrink' kernel boot parameter; and self-ballooning
+	  with the 'tmem.selfshrink=0' kernel boot parameter; and self-ballooning
 	  is enabled by default but can be disabled with the 'noselfballooning'
 	  kernel boot parameter.  Note that systems without a sufficiently
 	  large swap device should not enable self-ballooning.

drivers/xen/xen-selfballoon.c

@@ -60,8 +60,8 @@
  * be enabled with the "selfballooning" kernel boot option; similarly
  * selfballooning is enabled by default if frontswap is configured and
  * can be disabled with the "noselfballooning" kernel boot option.  Finally,
- * when frontswap is configured, frontswap-selfshrinking can be disabled
- * with the "noselfshrink" kernel boot option.
+ * when frontswap is configured,frontswap-selfshrinking can be disabled
+ * with the "tmem.selfshrink=0" kernel boot option.
  *
  * Selfballooning is disallowed in domain0 and force-disabled.
  *
@@ -120,9 +120,6 @@ static DECLARE_DELAYED_WORK(selfballoon_worker, selfballoon_process);
 /* Enable/disable with sysfs. */
 static bool frontswap_selfshrinking __read_mostly;
 
-/* Enable/disable with kernel boot option. */
-static bool use_frontswap_selfshrink = true;
-
 /*
  * The default values for the following parameters were deemed reasonable
  * by experimentation, may be workload-dependent, and can all be
@@ -176,14 +173,6 @@ static void frontswap_selfshrink(void)
 	frontswap_shrink(tgt_frontswap_pages);
 }
 
-static int __init xen_nofrontswap_selfshrink_setup(char *s)
-{
-	use_frontswap_selfshrink = false;
-	return 1;
-}
-
-__setup("noselfshrink", xen_nofrontswap_selfshrink_setup);
-
 /* Disable with kernel boot option. */
 static bool use_selfballooning = true;