net: neterion: vxge: Fix wrong function name in comments

Fixes the following W=1 kernel build warning(s):

 drivers/net/ethernet/neterion/vxge/vxge-config.c:4895: warning: expecting prototype for vxge_hw_vpath_rx_doorbell_post(). Prototype was for vxge_hw_vpath_rx_doorbell_init() instead
 drivers/net/ethernet/neterion/vxge/vxge-main.c:1814: warning: expecting prototype for vxge_poll(). Prototype was for vxge_poll_msix() instead
 drivers/net/ethernet/neterion/vxge/vxge-main.c:4761: warning: expecting prototype for vxge_rem_nic(). Prototype was for vxge_remove() instead

Cc: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>