Some header files define structures like this one:
typedef const struct zio_checksum_info {
/* ... */
const char *ci_name;
} zio_abd_checksum_func_t;
So we can use `zio_abd_checksum_func_t` for const declarations now.
It's not needed that we use the `const` qualifier again like this:
`const zio_abd_checksum_func_t *varname;`
This patch solves the double const qualifiers, which were found by
smatch.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes#13961