Fix makefile to handle PATH variable with whitespaces.

If PATH variable contains paths with whitespaces this could lead to
build breackage. This change fixes this issue.

Signed-off-by: Eugene Rodionov <radius.evgeniy@gmail.com>

Author: rodionov

tools/lkl/Makefile

@@ -81,7 +81,7 @@ $(ASM_CONFIG): $(OUTPUT)include/kernel_config.h
 # rule to build lkl.o
 $(OUTPUT)lib/lkl.o: bin/stat $(ASM_CONFIG) $(DOT_CONFIG)
 # this workaround is for arm32 linker (ld.gold)
-	$(Q)export PATH=$(srctree)/tools/lkl/bin/:${PATH} ;\
+	$(Q)export PATH="$(srctree)/tools/lkl/bin/:${PATH}" ;\
 	$(MAKE) -C ../.. ARCH=lkl $(KOPT)
 	$(MAKE) -C ../.. ARCH=lkl $(KOPT) install INSTALL_PATH=$(OUTPUT)