gss: remove gss_release_cred_by_mech()

gss_release_cred_by_mech() was previously used by SPNEGO's implementation of
gss_set_neg_mechs(). This is now implemented in the mechanism glue. As we never
shipped gss_release_cred_by_mech(), it is safe to remove it and its exported
symbol.

lib/gssapi/gssapi/gssapi.h

@@ -1228,12 +1228,6 @@ gss_get_neg_mechs(
     gss_const_cred_id_t /* cred_handle */,
     gss_OID_set * /* mech_list */);
 
-GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
-gss_release_cred_by_mech(
-    OM_uint32 * /* minor_status */,
-    gss_cred_id_t /* cred_handle */,
-    gss_const_OID /* mech */);
-
 GSSAPI_LIB_FUNCTION void GSSAPI_LIB_CALL
 gss_set_log_function(void *ctx, void (*func)(void * ctx, int level, const char *fmt, va_list));
 

lib/gssapi/libgssapi-exports.def

@@ -83,7 +83,6 @@ EXPORTS
 	gss_release_buffer
 	gss_release_buffer_set
 	gss_release_cred
-	gss_release_cred_by_mech
 	gss_release_iov_buffer
 	gss_release_name
 	gss_release_oid

lib/gssapi/mech/cred.c

@@ -78,24 +78,3 @@ _gss_mg_alloc_cred(void)
 	return cred;
 }
 
-GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
-gss_release_cred_by_mech(OM_uint32 *minor_status,
-			 gss_cred_id_t cred_handle,
-			 gss_const_OID mech_oid)
-{
-	struct _gss_cred *cred = (struct _gss_cred *)cred_handle;
-	struct _gss_mechanism_cred *mc, *next;
-	OM_uint32 major_status = GSS_S_NO_CRED;
-
-	*minor_status = 0;
-
-	HEIM_TAILQ_FOREACH_SAFE(mc, &cred->gc_mc, gmc_link, next) {
-		if (gss_oid_equal(mech_oid, mc->gmc_mech_oid)) {
-			HEIM_TAILQ_REMOVE(&cred->gc_mc, mc, gmc_link);
-			major_status = release_mech_cred(minor_status, mc);
-			break;
-		}
-	}
-
-	return major_status;
-}

lib/gssapi/version-script.map

@@ -77,7 +77,6 @@ HEIMDAL_GSS_2.0 {
 		gss_release_buffer;
 		gss_release_buffer_set;
 		gss_release_cred;
-		gss_release_cred_by_mech;
 		gss_release_iov_buffer;
 		gss_release_name;
 		gss_release_oid;