CVE-2022-49947 binder: fix alloc->vma_vm_mm null-ptr dereference

In the Linux kernel, the following vulnerability has been resolved: binder: fix alloc-vmavmmm null-ptr dereference Syzbot reported a couple issues introduced by commit 44e602b4e52f "binderalloc: add missing mmaplock calls when using the VMA", in which we attempt to acquire the mmaplock when...