f2fs crypto: clean up error handling in f2fs_fname_setup_filename
f2fs crypto: clean up error handling in f2fs_fname_setup_filename

Sync with:
  ext4 crypto: clean up error handling in ext4_fname_setup_filename

Signed-off-by: Jaegeuk Kim <71255387a32c360dfbe6dfb7aaeb123bf1dc8cb6@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs