apparmor: Remove SECURITY_APPARMOR_BOOTPARAM_VALUE

In preparation for removing CONFIG_DEFAULT_SECURITY, this removes the
soon-to-be redundant SECURITY_APPARMOR_BOOTPARAM_VALUE. Since explicit
ordering via CONFIG_LSM or "lsm=" will define whether an LSM is enabled or
not, this CONFIG will become effectively ignored, so remove it. However,
in order to stay backward-compatible with "security=apparmor", the enable
variable defaults to true.
Signed-off-by: Kees Cook <keescook@chromium.org>

security/apparmor/Kconfig

@@ -14,22 +14,6 @@ config SECURITY_APPARMOR
 
 	  If you are unsure how to answer this question, answer N.
 
-config SECURITY_APPARMOR_BOOTPARAM_VALUE
-	int "AppArmor boot parameter default value"
-	depends on SECURITY_APPARMOR
-	range 0 1
-	default 1
-	help
-	  This option sets the default value for the kernel parameter
-	  'apparmor', which allows AppArmor to be enabled or disabled
-          at boot.  If this option is set to 0 (zero), the AppArmor
-	  kernel parameter will default to 0, disabling AppArmor at
-	  boot.  If this option is set to 1 (one), the AppArmor
-	  kernel parameter will default to 1, enabling AppArmor at
-	  boot.
-
-	  If you are unsure how to answer this question, answer 1.
-
 config SECURITY_APPARMOR_HASH
 	bool "Enable introspection of sha1 hashes for loaded profiles"
 	depends on SECURITY_APPARMOR

security/apparmor/lsm.c

@@ -1333,7 +1333,7 @@ bool aa_g_paranoid_load = true;
 module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
 
 /* Boot time disable flag */
-static int apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
+static int apparmor_enabled __lsm_ro_after_init = 1;
 module_param_named(enabled, apparmor_enabled, int, 0444);
 
 static int __init apparmor_enabled_setup(char *str)