UPSTREAM: of: property: Fix the semantics of of_is_ancestor_of()

The of_is_ancestor_of() function was renamed from of_link_is_valid()
based on review feedback. The rename meant the semantics of the function
had to be inverted, but this was missed in the earlier patch.

So, fix the semantics of of_is_ancestor_of() and invert the conditional
expressions where it is used.

Fixes: a3e1d1a7f5fc ("of: property: Add functional dependency link from DT bindings")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191120080230.16007-1-saravanak@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry-picked from 3883539140b8ce67ad000938c3cd3b3e59498520)
Change-Id: I6ba531820df33c6a555990e02c08d96820ed8a4f