pzstd cannot decompress multiple files when supplied --stdout

[gcflymoto]

Describe the bug
pzstd cannot decompress multiple files when supplied --stdout.

To Reproduce
Two file .zst files in the same location and run
% pzstd --stdout -d *.pzstd.zst
Cannot specify an output file when handling multiple inputs

Expected behavior
Behave as zstd would

Desktop (please complete the following information):

• OS: SUSE
• Version SUSE12
• Compiler clang12

Workaround
Feed pzstd one file at a time

[terrelln]

pzstd is in maintenance-only mode. We aren't adding new features, and are just fixing bugs. You could likely use xargs to achieve this functionality.