Fix two cases involving opt_capsicum.h and module builds:

(1) opt_capsicum.h is no longer required in ffs_alloc.c, so remove the
   #include.

(2) portalfs depends on opt_capsicum.h, so have the Makefile generate one
   if required.

These affect only modules built without a kernel (i.e, not buildkernel,
but yes buildworld if the dubious MODULES_WITH_WORLD is used).

Approved by:	re (bz)
Sponsored by:	Google Inc

sys/modules/portalfs/Makefile

@@ -4,6 +4,7 @@
 
 KMOD=	portalfs
 SRCS=	vnode_if.h \
-	portal_vfsops.c portal_vnops.c
+	portal_vfsops.c portal_vnops.c \
+	opt_capsicum.h
 
 .include <bsd.kmod.mk>

sys/ufs/ffs/ffs_alloc.c

@@ -62,7 +62,6 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include "opt_capsicum.h"
 #include "opt_quota.h"
 
 #include <sys/param.h>