make: fix wildcard condition
@@ -10,7 +10,7 @@ SE=arm-none-eabi-size
GCC_VERSION = $(shell arm-none-eabi-gcc -dumpversion)
GIT_VERSION = unkown
-ifeq (,$(wildcard .git/refs/heads/master))
+ifneq (,$(wildcard .git/refs/heads/master))
GIT_VERSION = $(shell cat .git/refs/heads/master)
endif
