Revert "parse: check for NULL input"

This reverts commit 9387e61b5fcfbce1e4ed29b0cd19890a37ba1766.

Some callbacks do handle and expect the input to be NULL, so
unfortunately we cannot rely on that to do a generic punt for a NULL
input.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 file changed