runtime: fix makemap calls in __go_construct_map

The signature of makemap changed with the update to 1.10beta1,
but I forgot to update the call from C code.

Change-Id: I07a229510d299ec7a5854946fd7298220dbe7978
Reviewed-on: https://go-review.googlesource.com/87135
Reviewed-by: Than McIntosh <thanm@google.com>
1 file changed