[updateDaemon] Convert readdir_r to readdir
[updateDaemon] Convert readdir_r to readdir

Use of readdir_r yields deprecated function warnings.

* framework/c/src/updateDaemon/app.c (app_FinishUpdates):
readdir_r replaced with readdir.  Remove curEntry local variable;
re-purpose the curEntryPtr variable, previously an error-indicating
helper, as the directory entry iterator: occurrences of curEntry.d_name
and other member accesses become curEntryPtr->d_name. Also
initializing errno to zero. Currently, errno isn't checked after
a failed readdir, but in the future someone could add that and
forget to clear errno. We have to clear errno on every iteration,
because actions in the loop body can call library functions that
could make errno nonzero.

Resolves: LXSWIREF-91
Related: LE-6715
Change-Id: I8171f9a6c8b6a6d861bd1e4d85bc9ba3855ede33

legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af