Remove unused variables from Makefile.

Makefile

@@ -41,21 +41,9 @@ ifeq ($(findstring error,$(VERSION)), error)
 $(error "version_helper failed")
 endif
 
-# Get the branch information from git
-ifneq ($(shell which git),)
-GIT_DATE := $(shell git log -n 1 --format="%ci")
-GIT_HASH := $(shell git log -n 1 --format="%h")
-GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD | sed 's/[-_.\/]//g')
-GITINFO = .$(GIT_HASH).$(GIT_BRANCH)
-else
-GITINFO = ""
-endif
-
 ifeq ($(shell echo $(OS) | egrep -c 'Darwin|FreeBSD|OpenBSD|DragonFly'),1)
-DATE := $(shell date -j -r $(shell git log -n 1 --format="%ct") +%Y%m%d%H%M)
 CPUS ?= $(shell sysctl hw.ncpu|awk '{print $$2}')
 else
-DATE := $(shell date --utc --date="$(GIT_DATE)" +%Y%m%d%H%M)
 CPUS ?= $(shell nproc)
 endif