beckham: set path for $MY_DIR in extract scripts

Without setting $MY_DIR variable, patching blobs would fail
as the incorrect path would be set for LINEAGE_ROOT

This is a fixup of commit: 22f5cb1ba0758ae51c03caccd556e5a57456b5ad

Change-Id: Ib7d07f87bad3786aedcf8948419255d27aae07ce

extract-files.sh

@@ -19,6 +19,11 @@
 # stop right here. No need to go down the rabbit hole.
 if [ "${BASH_SOURCE[0]}" != "${0}" ]; then
     return
+else
+    MY_DIR="${BASH_SOURCE%/*}"
+    if [ ! -d "${MY_DIR}" ]; then
+        MY_DIR="${PWD}"
+    fi
 fi
 
 set -e
@@ -33,7 +38,7 @@ export DEVICE_BRINGUP_YEAR=2018
 
 "./../../${VENDOR}/${DEVICE_COMMON}/extract-files.sh" "$@"
 
-BLOB_ROOT="$LINEAGE_ROOT"/vendor/"$VENDOR"/"$DEVICE"/proprietary
+BLOB_ROOT="$LINEAGE_ROOT"/vendor/"${VENDOR}"/"${DEVICE}"/proprietary
 
 # Load ZAF configs from vendor
 ZAF_CORE="$BLOB_ROOT"/vendor/lib/libzaf_core.so