raidz_parity_verify
n = raidz_parity_verify(rm);
n = raidz_parity_verify(rm);
(void) raidz_parity_verify(rm);
n = raidz_parity_verify(zio, rm);
n = raidz_parity_verify(zio, rm);
(void) raidz_parity_verify(zio, rm);