include: use $(DIR_SUFFIX) in $(KERNEL_BUILD_DIR) to separate build_dir/linux-* directories when building different libc implementations in the same buildroot

SVN-Revision: 34299

include/kernel.mk

@@ -33,7 +33,7 @@ else
     PATCH_DIR ?= ./patches$(if $(wildcard ./patches-$(KERNEL_PATCHVER)),-$(KERNEL_PATCHVER))
     FILES_DIR ?= $(foreach dir,$(wildcard ./files ./files-$(KERNEL_PATCHVER)),"$(dir)")
   endif
-  KERNEL_BUILD_DIR ?= $(BUILD_DIR_BASE)/linux-$(BOARD)$(if $(SUBTARGET),_$(SUBTARGET))$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
+  KERNEL_BUILD_DIR ?= $(BUILD_DIR_BASE)/linux-$(BOARD)$(if $(SUBTARGET),_$(SUBTARGET))$(DIR_SUFFIX)$(if $(BUILD_SUFFIX),_$(BUILD_SUFFIX))
   LINUX_DIR ?= $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)
 
   LINUX_VERMAGIC:=$(strip $(shell cat $(LINUX_DIR)/.vermagic 2>/dev/null))