bcachefs: Allocate some extra room in btree_key_cache_fill()

If we allocate a buffer that's a bit bigger than necessary the
transaction commit path will be much less likely to have to reallocate -
which requires a transaction restart.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-04-17 17:50:47 -04:00 • committed by Kent Overstreet
commit a729e489ab