[Doc] C data interface example for i32 uses `l`, not `i`, in the format

[asfimport]

The specification uses "i" to represent i32, but the example uses "l" (i64).

Reporter: Jorge Leitão / @jorgecarleitao
Assignee: Jorge Leitão / @jorgecarleitao

PRs and other links:

• GitHub Pull Request #8357

_{Note: This issue was originally created as ARROW-10189. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 8357
#8357