force event socket buffer size to 16MB

force event socket buffer size to 16MB

Netlink events get lost when the kernel creates thousends of events
faster than udevd reads it. The default is 128 KB, which can carry
app. 500 events. Set it to 16 MB now.

  I have 4000 fibrechannel LUNs connected to my system.  There are two
  paths to the devices and two ports on the host connected via a switch.
  This gives 16000 when probed.
  I have had problems getting all of the entries in /dev created.
  -- Mark Haverkamp <markh@osdl.org>

Signed-off-by: Kay Sievers <kay.sievers@suse.de>