unconfined: remove linux_immutable

As far as I know, this is never used. Get rid of it.

Change-Id: Iee0fb4e3f3952a0c4cc28d0aa96ca6c462ba5211

unconfined.te

@@ -16,7 +16,7 @@
 # The use of this template is discouraged.
 ######################################################
 
-allow unconfineddomain self:capability ~{ sys_ptrace sys_rawio mknod sys_module audit_write audit_control };
+allow unconfineddomain self:capability ~{ sys_ptrace sys_rawio mknod sys_module audit_write audit_control linux_immutable };
 allow unconfineddomain self:capability2 ~{ mac_override mac_admin };
 allow unconfineddomain kernel:security ~{ load_policy setenforce setcheckreqprot setbool setsecparam };
 allow unconfineddomain kernel:system *;