console: fix usage of an undeclared variable

Console client's eval() method in case of an error at
reading from a socket was trying to return a variable
declared in a different view scope. Instead, the
error should be raised to drop the connection.

Reviewed-by: Alexander Turenko <alexander.turenko@tarantool.org>
(cherry picked from commit 89ec1d97)

src/box/lua/console.lua

@@ -451,7 +451,7 @@ local text_connection_mt = {
                     self.print_f(rc)
                 end
             end
-            return rc
+            return error(self:set_error())
         end,
         --
         -- Make the connection be in error state, set error