Fix possible access of uninitialized pipe handles

Fix possible access of uninitialized pipe handles

Compile time warning for openvpnserv.exe
interactive.c: In function ‘RunOpenvpn’:
interactive.c:160:27: warning: ‘svc_pipe’ may be used uninitialized in
this function [-Wmaybe-uninitialized]

When RunOpenvpn exits early due to errors, uninitialized svc_pipe and
ovpn_pipe vars could get passed to CloseHandleEx(). Fix by initializing
to NULL.

Signed-off-by: Selva Nair <selva.nair@gmail.com>
Acked-by: Lev Stipakov <lstipakov@gmail.com>
Message-Id: <1582163803-3342-1-git-send-email-selva.nair@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg19480.html
Signed-off-by: David Sommerseth <davids@openvpn.net>