Socket ReceiveBufferSize & SendBufferSize set to random values.

Fixes :

https://bugzilla.xamarin.com/show_bug.cgi?id=16021
https://bugzilla.xamarin.com/show_bug.cgi?id=12754

Resolves:

http://lists.ximian.com/pipermail/mono-list/2013-June/050008.html

A reference to the variable bufsize, local to the else-if block was being passed to the function setsockopt hence
the properties ReceiveBufferSize & SendBufferSize were being set to garbage on the Socket class. This could and did have a SERIOUS performance hit on socket communication. It is not inconceivable that people would try to increase the
buffer sizes and inadvertently shrink them considerably with a consequence of drastically degrade performance.

Narinder Claire
narinder.claire <> gmail.com

Signed-off-by: Narinder CLAIRE <narinder.claire@uk.bnpparibas.com>