[source] build: remove obsolete variables from opkg command

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=37e82e4e42155901756a67ad14f3d5c1335f3b0a

commit 37e82e4e42155901756a67ad14f3d5c1335f3b0a
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Fri Jul 22 12:04:33 2016 +0200

    build: remove obsolete variables from opkg command
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/rootfs.mk                  | 3 ---
 target/imagebuilder/files/Makefile | 3 ---
 2 files changed, 6 deletions(-)

diff --git a/include/rootfs.mk b/include/rootfs.mk
index ac8f04d..4b4482c 100644
--- a/include/rootfs.mk
+++ b/include/rootfs.mk
@@ -36,10 +36,7 @@ endif
 # where to build (and put) .ipk packages
 OPKG:= \
   IPKG_NO_SCRIPT=1 \
-  IPKG_TMP=$(TMP_DIR)/ipkg \
   IPKG_INSTROOT=$(TARGET_DIR) \
-  IPKG_CONF_DIR=$(STAGING_DIR)/etc \
-  IPKG_OFFLINE_ROOT=$(TARGET_DIR) \
   $(XARGS) $(STAGING_DIR_HOST)/bin/opkg \
 	--offline-root $(TARGET_DIR) \
 	--force-depends \
diff --git a/target/imagebuilder/files/Makefile b/target/imagebuilder/files/Makefile
index 4ae0297..4443985 100644
--- a/target/imagebuilder/files/Makefile
+++ b/target/imagebuilder/files/Makefile
@@ -56,10 +56,7 @@ PACKAGE_DIR:=$(TOPDIR)/packages
 LISTS_DIR:=$(subst $(space),/,$(patsubst %,..,$(subst /,$(space),$(TARGET_DIR))))$(DL_DIR)
 OPKG:= \
   IPKG_NO_SCRIPT=1 \
-  IPKG_TMP="$(TMP_DIR)/ipkgtmp" \
   IPKG_INSTROOT="$(TARGET_DIR)" \
-  IPKG_CONF_DIR="$(TMP_DIR)" \
-  IPKG_OFFLINE_ROOT="$(TARGET_DIR)" \
   $(STAGING_DIR_HOST)/bin/opkg \
 	-f $(TOPDIR)/repositories.conf \
 	--force-depends \