Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull kbuild fixes from Michal Marek:
 "Two fixes for kbuild:

   - The new ARCH_{CPP,A,C}FLAGS variables are reset before including
     the arch Makefile

   - Fix calling make modules_install twice when module compression is
     enabled"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  Makefile: Force gzip and xz on module install
  kbuild: Do not pick up ARCH_{CPP,A,C}FLAGS from the environment

Makefile

@@ -597,6 +597,11 @@ endif # $(dot-config)
 # Defaults to vmlinux, but the arch makefile usually adds further targets
 all: vmlinux
 
+# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
+# values of the respective KBUILD_* variables
+ARCH_CPPFLAGS :=
+ARCH_AFLAGS :=
+ARCH_CFLAGS :=
 include arch/$(SRCARCH)/Makefile
 
 KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
@@ -848,10 +853,10 @@ export mod_strip_cmd
 mod_compress_cmd = true
 ifdef CONFIG_MODULE_COMPRESS
   ifdef CONFIG_MODULE_COMPRESS_GZIP
-    mod_compress_cmd = gzip -n
+    mod_compress_cmd = gzip -n -f
   endif # CONFIG_MODULE_COMPRESS_GZIP
   ifdef CONFIG_MODULE_COMPRESS_XZ
-    mod_compress_cmd = xz
+    mod_compress_cmd = xz -f
   endif # CONFIG_MODULE_COMPRESS_XZ
 endif # CONFIG_MODULE_COMPRESS
 export mod_compress_cmd