Fix modify deadlock

servers/slapd/overlays/syncprov.c

@@ -1080,7 +1080,6 @@ syncprov_op_cleanup( Operation *op, SlapReply *rs )
 	mtdummy.mt_op = op;
 	ldap_pvt_thread_mutex_lock( &si->si_mods_mutex );
 	mt = avl_find( si->si_mods, &mtdummy, sp_avl_cmp );
-	ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
 	if ( mt ) {
 		modinst *mi = mt->mt_mods;
 
@@ -1091,14 +1090,13 @@ syncprov_op_cleanup( Operation *op, SlapReply *rs )
 			mt->mt_op = mt->mt_mods->mi_op;
 			ldap_pvt_thread_mutex_unlock( &mt->mt_mutex );
 		} else {
-			ldap_pvt_thread_mutex_lock( &si->si_mods_mutex );
 			avl_delete( &si->si_mods, mt, sp_avl_cmp );
-			ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
 			ldap_pvt_thread_mutex_unlock( &mt->mt_mutex );
 			ldap_pvt_thread_mutex_destroy( &mt->mt_mutex );
 			ch_free( mt );
 		}
 	}
+	ldap_pvt_thread_mutex_unlock( &si->si_mods_mutex );
 	if ( !BER_BVISNULL( &opc->suuid ))
 		op->o_tmpfree( opc->suuid.bv_val, op->o_tmpmemctx );
 	if ( !BER_BVISNULL( &opc->sndn ))