include/kernel.mk - better search for ARCH

If "findstring" is used without leading and trailing spaces unexpected matches
may happen. For example consider ARC=arc then "findstring $(ARCH)" will
report a false match with "aarch64".

But "findstring $ARCH " (note trailing space) will correctly skip
matches for both "aarch64" and "aarch64_be".

This patch is built-tested against NetGear WNDR3800.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Cc: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 47359

include/kernel.mk

@@ -62,15 +62,15 @@ endif
 
 ifneq (,$(findstring uml,$(BOARD)))
   LINUX_KARCH=um
-else ifneq (,$(findstring $(ARCH), aarch64 aarch64_be))
+else ifneq (,$(findstring $(ARCH) , aarch64 aarch64_be ))
   LINUX_KARCH := arm64
-else ifneq (,$(findstring $(ARCH), armeb))
+else ifneq (,$(findstring $(ARCH) , armeb ))
   LINUX_KARCH := arm
-else ifneq (,$(findstring $(ARCH), mipsel mips64 mips64el))
+else ifneq (,$(findstring $(ARCH) , mipsel mips64 mips64el ))
   LINUX_KARCH := mips
-else ifneq (,$(findstring $(ARCH), sh2 sh3 sh4))
+else ifneq (,$(findstring $(ARCH) , sh2 sh3 sh4 ))
   LINUX_KARCH := sh
-else ifneq (,$(findstring $(ARCH), i386 x86_64))
+else ifneq (,$(findstring $(ARCH) , i386 x86_64 ))
   LINUX_KARCH := x86
 else
   LINUX_KARCH := $(ARCH)