Revert "driver core: Rename dev_links_info.defer_sync to defer_hook"

Revert "driver core: Rename dev_links_info.defer_sync to defer_hook"

This reverts commit ec7bd78498f29680f536451fbdf9464e851273ed.

This field rename was done to reuse defer_syc list head for multiple
lists. That's not needed anymore and this list head will only be used
for defer sync. So revert this patch to avoid conflicts with the other
reverts coming after this.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>