fix typos in comments

[codecov-commenter]

Codecov Report

Patch coverage is 100.00% of modified lines.

:exclamation: Your organization is not using the GitHub App Integration. As a result you may experience degraded service beginning May 15th. Please install the GitHub App Integration for your organization. Read more.

Files Changed	Coverage
src/vec.rs	ø
src/dynamic.rs	100.00%

:loudspeaker: Thoughts on this report? Let us know!.

[laurmaedje]

Thanks!