mm: remove unnecessary indirection

mm: remove unnecessary indirection

Now we removed the merge logic from __mmap_new_file_vma() we can simply
pass in the vma direct rather than a pointer to a VMA, as pointed out by
Vlastimil.

Link: https://lkml.kernel.org/r/5106696d-e625-4d8a-8545-9d1430301730@lucifer.local
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>