Fix FLIPPEDSWI call in gen_initial_workspace

In gen_initial_workspace/script_initial_workspace.sh, before anything else is done, it is checked if $CONFDATA/ID_FLIPPEDSWI.txt has been created, and if not, a serial computation is called to create this file with ./gen_FLIPPEDSWI/script_FLIPPEDSWI_serial.sh. However, the script is called directly without switching directories, resulting in a failure to find ./script_FLIPPEDSWI_subject.sh when called within script_FLIPPEDSWI_serial.sh

This PR adds the needed change of directories to let this run.

generate_initial_data/gen_initial_workspace/script_initial_workspace.sh

@@ -3,7 +3,9 @@
 # Note: Needs a directory with DICOMs
 
 if [ ! -f $CONFDATA/ID_FLIPPEDSWI.txt ] ; then
-    ../gen_FLIPPEDSWI/script_FLIPPEDSWI_serial.sh
+    cd ../gen_FLIPPEDSWI
+    ./script_FLIPPEDSWI_serial.sh
+    cd ../gen_initial_workspace
 fi
 
 for elem in `cat $CONFDATA/subj.txt` ; do