Fix memory leak in SPNEGO gss_init_sec_context()

Fix memory leak in SPNEGO gss_init_sec_context()

After the initial call to spnego_gss_init_sec_context(), the context
handle can leak if init_ctx_cont() returns an error, because the
cleanup handler assumes that spnego_ctx contains the value of
*context_handle.  Fix this leak by setting spnego_ctx before the if
block which contains that call.  Reported by Adam Bernstein.

(cherry picked from commit 159dbbd5ff14fdc2fa71fb3a8804eb401c914399)

ticket: 8281
version_fixed: 1.13.4
tags: -pullup
status: resolved