There's a bug in the function. When closing a stream, the stream
refcount should be decremented. We have a helper function for that
which (among others) take a virConnectPtr as an argument. However,
we are passing an internal representation of the virConnect.
Even gcc warns about this:

libvirt-php.c: In function ‘zif_libvirt_stream_close’:
libvirt-php.c:3748:47: warning: passing argument 2 of ‘resource_change_counter’ from incompatible pointer type
  resource_change_counter(INT_RESOURCE_STREAM, stream->conn, stream->stream, 0 TSRMLS_CC);
                                               ^
libvirt-php.c:470:5: note: expected ‘virConnectPtr’ but argument is of type ‘struct php_libvirt_connection *’
 int resource_change_counter(int type, virConnectPtr conn, void *memp, int inc TSRMLS_DC)
     ^
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>