[source] opkg: use default PKG_BUILD_DIR

[LEDE Commits]

neoraider pushed a commit to source.git, branch master:
https://git.lede-project.org/621fd9fd62b8e405c43eb9d94ac2f9a8524c0496

commit 621fd9fd62b8e405c43eb9d94ac2f9a8524c0496
Author: Matthias Schiffer <mschiffer at universe-factory.net>
AuthorDate: Mon Jan 16 09:02:42 2017 +0100

    opkg: use default PKG_BUILD_DIR
    
    opkg doesn't have BUILD_VARIANTs anymore, so the previously defined
    PKG_BUILD_DIR would lead to a weird 'opkg-' path component.
    
    Signed-off-by: Matthias Schiffer <mschiffer at universe-factory.net>
---
 package/system/opkg/Makefile | 1 -
 1 file changed, 1 deletion(-)

diff --git a/package/system/opkg/Makefile b/package/system/opkg/Makefile
index 898d769..15d4ea0 100644
--- a/package/system/opkg/Makefile
+++ b/package/system/opkg/Makefile
@@ -18,7 +18,6 @@ PKG_SOURCE_URL:=http://git.yoctoproject.org/git/opkg
 PKG_SOURCE_DATE:=2011-04-08
 PKG_SOURCE_VERSION:=9c97d5ecd795709c8584e972bfdf3aee3a5b846d
 PKG_MIRROR_HASH:=55e05270f3eb2f3aff5d3791463ce3d13b8197ca7b301cd58e731a249552c48f
-PKG_BUILD_DIR=$(BUILD_DIR)/$(PKG_NAME)-$(BUILD_VARIANT)/$(PKG_NAME)-$(PKG_VERSION)
 PKG_FIXUP:=autoreconf
 PKG_REMOVE_FILES = autogen.sh aclocal.m4