mv: handle FIFOs inside directories during cross-partition move

[ChrisDryden]

There was a new test added to the gnu mv suite that validates the behavior that for FIFO's when copied across partitions that they stay FIFO's. This should fix test/mv/mv-special-1

[oech3]

#9656 ?

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/mv/mv-special-1 is no longer failing!
Congrats! The gnu test tests/pr/bounded-memory is no longer failing!

[github-actions]

GNU testsuite comparison:

Congrats! The gnu test tests/mv/mv-special-1 is no longer failing!
Note: The gnu test tests/expand/bounded-memory is now being skipped but was previously passing.
Note: The gnu test tests/pr/bounded-memory is now being skipped but was previously passing.

[oech3]

$ mv a /tmp/a
mv: Operation not supported (os error 95)

FIFO was copied, but stil lfails. Maybe, a exists on compressed Btrfs?