- remove needless return
- remove needless format!
- remove a few more needless clone()
- from_str_radix(_, 10) -> .parse()
- remove needless reference
- remove needless `mut`
Also manually replaced a match statement with map_err() because after
clippy was done with it, there was almost nothing left in the match
expression.
The postgres_ext.h isn't found in vendor/postgres, if the Postgres
was restored from cache instead of building it in vendor/postgres.
To fix, change include path to point into tmp_install/include where the
headers are installed, instead of the vendor/postgres source dir.
