make: Simplify ARCH retrieval

Actually the former code was being expanding
uname_M variable which is not set that early
(this was not a problem since we assign it a
line below, still it was a dead code which
should be fixed).

Also update

 | ifeq ($(findstring arm,$(ARCH)),arm)

to simple

 | ifeq ($(ARCH),arm)
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makefile

@@ -24,25 +24,31 @@ SH		:= bash
 MAKE		:= make
 OBJCOPY		:= objcopy
 
-# Additional ARCH settings for x86
-ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
-                  -e s/arm.*/arm/ -e s/sa110/arm/ \
-                  -e s/s390x/s390/ -e s/parisc64/parisc/ \
-                  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
-                  -e s/sh[234].*/sh/ )
-
-uname_M      := $(shell uname -m | sed -e s/i.86/i386/)
-ifeq ($(uname_M),i386)
+#
+# Fetch ARCH from the uname if not yet set
+#
+ARCH ?= $(shell uname -m | sed		\
+		-e s/i.86/i386/		\
+		-e s/sun4u/sparc64/	\
+		-e s/arm.*/arm/		\
+		-e s/sa110/arm/		\
+		-e s/s390x/s390/	\
+		-e s/parisc64/parisc/	\
+		-e s/ppc.*/powerpc/	\
+		-e s/mips.*/mips/	\
+		-e s/sh[234].*/sh/)
+
+ifeq ($(ARCH),i386)
 	ARCH         := x86-32
 	DEFINES      := -DCONFIG_X86_32
 endif
-ifeq ($(uname_M),x86_64)
+ifeq ($(ARCH),x86_64)
 	ARCH         := x86
 	DEFINES      := -DCONFIG_X86_64
 	LDARCH       := i386:x86-64
 endif
 
-ifeq ($(findstring arm,$(uname_M)),arm)
+ifeq ($(ARCH),arm)
 	ARCH         := arm
 	ARCH_DEFINES := -DCONFIG_ARM
 	LDARCH       := arm