docs: selinux: add '=' signs to kernel boot options

Provide the full kernel boot option string (with ending '=' sign).
They won't work without that and that is how other boot options are
listed.

If used without an '=' sign (as listed here), they cause an "Unknown
parameters" message and are added to init's argument strings,
polluting them.

  Unknown kernel command line parameters "enforcing checkreqprot
    BOOT_IMAGE=/boot/bzImage-517rc6", will be passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
     enforcing
     checkreqprot
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: selinux@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
[PM: removed bogus 'Fixes' line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -550,7 +550,7 @@
 			nosocket -- Disable socket memory accounting.
 			nokmem -- Disable kernel memory accounting.
 
-	checkreqprot	[SELINUX] Set initial checkreqprot flag value.
+	checkreqprot=	[SELINUX] Set initial checkreqprot flag value.
 			Format: { "0" | "1" }
 			See security/selinux/Kconfig help text.
 			0 -- check protection applied by kernel (includes
@@ -1439,7 +1439,7 @@
 			(in particular on some ATI chipsets).
 			The kernel tries to set a reasonable default.
 
-	enforcing	[SELINUX] Set initial enforcing status.
+	enforcing=	[SELINUX] Set initial enforcing status.
 			Format: {"0" | "1"}
 			See security/selinux/Kconfig help text.
 			0 -- permissive (log only, no denials).