r8169: remove rtl8169_reinit_task.

r8169: remove rtl8169_reinit_task.

I see no good reason to keep both rtl8169_reinit_task and rtl8169_reset_task:
- rtl8169_reinit_task adds a software failure point which does relate to
  any hardware state
- they handle hardware the same. Remember that rtl8169_reinit_task was
  introduced in the 8169 only era to handle PCI errors way before the 8168
  asked for pll and firmware ops and compare :

      rtl8169_reinit_task     |    rtl8169_reset_task
  ----------------------------+--------------------------
  rtl8169_wait_for_quiescence | rtl8169_hw_reset
  rtl8169_update_counters     | rtl8169_wait_for_quiescence
  rtl8169_hw_reset            | rtl_hw_start
  rtl8169_rx_missed           | rtl8169_check_link_status
  rtl_pll_power_down          |
  rtl_request_firmware        |
  rtl8169_init_phy            |
  rtl_pll_power_up            |
  rtl_hw_start                |
  rtl8169_check_link_status   |

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Hayes Wang <hayeswang@realtek.com>