package/tekui: really disable parallel build

Commit "c80789c917 tekui: disable parallel build" added TEKUI_MAKE but
that is not a symbol used by the generic package infra.

Ensure -j1 is passed to the build and install commands by using
TEKUI_MAKE explicitly.

Fixes:
http://autobuild.buildroot.net/results/c6cd0d488581013a8b215b0ee2fd8f549a868d4b

Cc: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tekui/tekui.mk

@@ -59,11 +59,11 @@ endif
 endif
 
 define TEKUI_BUILD_CMDS
-	$(TARGET_MAKE_ENV) $(MAKE) $(TEKUI_MAKE_OPTS) PREFIX="/usr" -C $(@D) all
+	$(TARGET_MAKE_ENV) $(TEKUI_MAKE) $(TEKUI_MAKE_OPTS) PREFIX="/usr" -C $(@D) all
 endef
 
 define TEKUI_INSTALL_TARGET_CMDS
-	$(TARGET_MAKE_ENV) $(MAKE) $(TEKUI_MAKE_OPTS) PREFIX="$(TARGET_DIR)/usr" -C $(@D) install
+	$(TARGET_MAKE_ENV) $(TEKUI_MAKE) $(TEKUI_MAKE_OPTS) PREFIX="$(TARGET_DIR)/usr" -C $(@D) install
 endef
 
 $(eval $(generic-package))