Revert "BufWritePre should be <buffer>"
Revert "BufWritePre should be <buffer>"

The fix for the problem mentioned in e84cfa945ce894f6faf5 was the actual
root cause of the original issue. Reverting this fixes a bug, as
suggested by @dbger in #300.

This reverts commit e2cf315fb89dfcc3050da1a885129b1baa7f4889.

rust-lang/rust.vim