Makefile: make exported variable definitions consistent

Use a space before and after the equal sign when defining the TZ, LANG
and LC_ALL variables, as suggested by the Buildroot coding style.

Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Makefile

@@ -248,9 +248,9 @@ endif
 
 # timezone and locale may affect build output
 ifeq ($(BR2_REPRODUCIBLE),y)
-export TZ=UTC
-export LANG=C
-export LC_ALL=C
+export TZ = UTC
+export LANG = C
+export LC_ALL = C
 export GZIP = -n
 BR2_VERSION_GIT_EPOCH = $(shell GIT_DIR=$(TOPDIR)/.git $(GIT) log -1 --format=%at)
 export SOURCE_DATE_EPOCH = $(if $(wildcard $(TOPDIR)/.git),$(BR2_VERSION_GIT_EPOCH),$(BR2_VERSION_EPOCH))