s3store fix incomplete part keys

[butonic]

When using a different prefix for metadata files uploads break because the code sometimes uses metadataKeyWithPrefix when it should use keyWithPrefix.

Unless I understood something completely wrong and failed to understand what the debug session was trying to tell me ;-)

[Acconut]

Thank you for this PR, but I am not too sure about this change. The documentation clearly states that the metadata prefix will be used for the .part object:

tusd/pkg/s3store/s3store.go

Lines 107 to 113 in c856f72

	// ObjectPrefix is prepended to the name of each S3 object that is created
	// to store uploaded files. It can be used to create a pseudo-directory
	// structure in the bucket, e.g. "path/to/my/uploads".
	ObjectPrefix string
	// MetadataObjectPrefix is prepended to the name of each .info and .part S3
	// object that is created. If it is not set, then ObjectPrefix is used.
	MetadataObjectPrefix string

IIRC, the idea is that the object prefix defines the prefix for the completed file uploads. All additional objects (e.g. .info and .part) will be put under the metadata prefix.

[Acconut]

Closing this issue due to inactivity. Feel free to leave a comment if you want to continue the discussion :)