If the `list_head()` returns NULL, we dereference it, right before we
check to see if it returned NULL.
We have defined two different pointers that both point to the same
thing, which are `origin_head` and `origin_ds`. Almost everything uses
`origin_ds`, so we switch them to use `origin_ds`.
We also promote `origin_ds` to a const pointer so that the compiler
verifies that nothing modifies it.
Coverity complained about this.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13967
c562bbefc0