[Bugfix]fix mk_sdk.sh can not extract files meta-sdk.tar.gz

Change-Id: I0ddd90c8f9e17c8a580a228d9eb9bbfab3c1d336
diff --git a/mk_sdk.sh b/mk_sdk.sh
index 0d58a17..7d10083 100755
--- a/mk_sdk.sh
+++ b/mk_sdk.sh
@@ -6,7 +6,7 @@
 ln -s ${TOPDIR}/downloads ./build/tmp/deploy/images/sdk/downloads
 ln -s ${TOPDIR}/meta-sdk/meta-sdk.tar.gz ./build/tmp/deploy/images/sdk/meta-sdk.tar.gz
 cd  ${TOPDIR}/build/tmp/deploy/images/sdk/
-tar -xzvf ./meta-sdk.tar.gz ./
+tar -xvf ./meta-sdk.tar.gz
 sleep 2s
 .  ./env-SDK.sh
 cd ../