x230: support running scripts from anywhere

change to working dir for the scripts that use util/.

x230/external_install_bottom.sh

@@ -7,6 +7,8 @@ NC='\033[0m'
 
 set -e
 
+cd "$(dirname "$0")"
+
 IFDTOOL_PATH=./util/ifdtool/ifdtool
 ME_CLEANER_PATH=./util/me_cleaner/me_cleaner.py
 have_chipname=0

x230/x230_heads.sh

@@ -4,6 +4,8 @@
 
 set -e
 
+cd "$(dirname "$0")"
+
 source "util/functions.sh"
 
 have_input_image=0

x230/x230_skulls.sh

@@ -4,6 +4,8 @@
 
 set -e
 
+cd "$(dirname "$0")"
+
 source "util/functions.sh"
 
 have_input_image=0