make: use single ticks

Otherwise the shell will try to evaluate the parentheses.
RIOT-OS · Mar 1, 2016 · 4c6b59b · 4c6b59b
1 parent c1b0713
commit 4c6b59b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/Makefile.include b/Makefile.include
@@ -179,7 +179,7 @@ ifeq ($(origin RIOT_VERSION), undefined)
       RIOT_VERSION := $(GIT_STRING)-$(GIT_BRANCH)
     endif
   else
-    RIOT_VERSION := "UNKNOWN (builddir: $(RIOTBASE))"
+    RIOT_VERSION := 'UNKNOWN (builddir: $(RIOTBASE))'
   endif
 endif