system: core: Remove previously created symlinks

When switching composition having more than 3 interfaces
to a composition defined in init.usb.configfs.rc, rule is
only removing f1, f2 and f3 symlinks. As a result old symlinks
remain present. If an interface which is present into both
compositions then new symlink is not getting created because
old symlink is already present. This is resulting into usb
device enumeration failure as device descriptor information
becomes invalid. Fix this issue by removing rest of the
previously created symlinks.

Change-Id: I4ad6a9d718c15fd325717834a665437e80042e1b