Also call IPSFactoryBuffer_Release on the 2nd arg, rather than on This->pPSFactory.

IRpcChannelBuffer_GetBuffer may put extra data onto the wire for ORPC
calls.

idenitfy what the code contained does - it is a number of helpers for
generated client/server code.

functions to cproxy.c since both sets of functions depend on the
implementations of the standard stubs and proxies.

which seems to be more appropriate and matches the errno translation
in ntdll.