winmad: fixup return values and zero allocated mad

winmad: fixup return values and zero allocated mad

Winmad simply returns the status values defined by IBAL.  Convert those values into winmad define status values and align those values with errno.  This matches the expectations of libibumad.

As part of the cleanup, convert the check for success from IB_SUCCESS to IB_WCS_SUCCESS.  Both are defined as 0, so there's no functional change,but the mad status is a 'work completion status' value, not an API status value.

Finally, return the correct status value when canceling a read request.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
git-svn-id: svn://openib.tc.cornell.edu/gen1@2823 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86