Rx warning removal

Rx warning removal

This patch set removes many but not all of the warnings
in the rx library.

 - use AFS_PTR_FMT in dpf debugging output

 - fix many signed vs unsigned warnings

 - on Windows, the first parameter to select() is ignored.
   Passing an osi_socket produces an unnecessary warning.

 - In rx_SlowReadPacket and rx_SlowWritePacket, use 'r' the
   unsigned value for internal computation and 'resid' for
   holding the original value.  This avoids many signed vs
   unsigned warnings.

LICENSE BSD

Reviewed-on: http://gerrit.openafs.org/695
Tested-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>