Description: Fix ARCH setting in modules Makefiles.
Author: Michael Meskes <meskes@debian.org>, Gianfranco Costamagna <locutusofborg@debian.org>

--- a/src/VBox/Installer/linux/Makefile-header.gmk
+++ b/src/VBox/Installer/linux/Makefile-header.gmk
@@ -45,7 +45,7 @@
 # (We have to support basic cross building (ARCH=i386|x86_64).)
 # While at it, warn about BUILD_* vars found to help with user problems.
 #
-ifeq ($(filter-out x86_64 amd64 AMD64,$(shell uname -m)),)
+ifeq ($(filter-out x86_64 amd64 AMD64,$(shell dpkg-architecture -qDEB_HOST_GNU_CPU)),)
  BUILD_TARGET_ARCH_DEF := amd64
 else
  BUILD_TARGET_ARCH_DEF := x86