selinux, kbuild: remove unnecessary $(hostprogs-y) from clean-files

Files added to hostprogs-y are cleaned. (See scripts/Makefile.clean)
Adding them to clean-files is redundant.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

scripts/selinux/genheaders/Makefile

@@ -2,4 +2,3 @@ hostprogs-y	:= genheaders
 HOST_EXTRACFLAGS += -Isecurity/selinux/include
 
 always		:= $(hostprogs-y)
-clean-files	:= $(hostprogs-y)

scripts/selinux/mdp/Makefile

@@ -2,4 +2,4 @@ hostprogs-y	:= mdp
 HOST_EXTRACFLAGS += -Isecurity/selinux/include
 
 always		:= $(hostprogs-y)
-clean-files	:= $(hostprogs-y) policy.* file_contexts
+clean-files	:= policy.* file_contexts