Warning fixes from Christos Zoulas

- shadowed variables
- signed/unsigned confusion
- const lossage
- incomplete structure initializations
- unused code

lib/gssapi/spnego/context_stubs.c

@@ -37,7 +37,7 @@ spnego_supported_mechs(OM_uint32 *minor_status, gss_OID_set *mechs)
 {
     OM_uint32 ret, junk;
     gss_OID_set m;
-    int i;
+    size_t i;
 
     ret = gss_indicate_mechs(minor_status, &m);
     if (ret != GSS_S_COMPLETE)
@@ -565,7 +565,7 @@ OM_uint32 GSSAPI_CALLCONV _gss_spnego_inquire_names_for_mech (
 {
     gss_OID_set mechs, names, n;
     OM_uint32 ret, junk;
-    int i, j;
+    size_t i, j;
 
     *name_types = NULL;