Fix type of malloc call in trans-expr.cc

[Jakub Jelinek]

On Fri, Nov 15, 2024 at 07:45:32AM +0000, Paul Richard Thomas wrote:
> Hi Jakub,

Honza's catch.

> Good catch! Does it fix any specific PR?

Dunno.  I think even without a PR it can be backported after a while.

	Jakub