nommu: fix memory leak in do_mmap() error path

nommu: fix memory leak in do_mmap() error path

This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven.
This ID is fixed in Linux Kernel version v6.1.8 by commit 1442d51026c58e7c11dd5f9b19650632a48676d4, it was introduced in version v6.1 by commit 8220543df1489ef96c3d4e8b0b3b03c340e3943e. For more details please see the references link.