autosave: drop autosave subdirectory in save path

This subdirectory was initially thought as a way to have a proper
namespace for autosave files among runtime variable data handled by the
IOC. It turns out though that no other data is actually generated. Drop
such namespace, as already expected by deploy scripts [1].

[1] lnls-dig/bpm-app@e6670fe

iocBoot/iocBPMRFFEApp/save_restore.cmd

@@ -9,7 +9,7 @@ save_restoreSet_DatedBackupFiles(1)
 save_restoreSet_NumSeqFiles(3)
 save_restoreSet_SeqPeriodInSeconds(300)
 
-set_savefile_path("/var/opt/rffe-epics-ioc", "autosave")
+set_savefile_path("/var/opt/rffe-epics-ioc", "")
 
 set_pass0_restoreFile("$(P)$(R)_settings.sav")
 set_pass1_restoreFile("$(P)$(R)_settings.sav")