When the typelib_TypeDescription is null, the following code would dereference a
null pointer anyway (but which doesn't necessarily cause an immediate crash on
some platforms like Wasm, so better be explicit). (Also, leave those checks out
of functions like uno_type_sequence_realloc, which would have been preceded by a
call to one of the functions creating a sequence of the given type, and which
would thus already have detected failure to obtain the relevant type
information.)
Change-Id: I36193ea837edeca451fd09a866623cf40d3cdb4d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163813
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>