deapexer: only print errors if call to debugfs fails

This suppresses expected noise like:
rdump: Operation not permitted while changing ownership of /tmp/deapexer//lost+found

Test: deapexer extract com.android.apex.cts.shim.v2.apex /tmp/deapexer
Test: verified stderr is empty
Bug: 145254037
Fixes: 145254037
Change-Id: I7449d8325d0d7ffb1bdc7a1f6eefccebca0970c1
1 file changed