The extra inclusion via xvattr.h appears to upset the linter in CI. I'm
not entirely sure what its complaint is, but removing sys/string.h
entirely is not quite possible yet, and include guards are rarely a bad
idea, so this will do.
Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes#17861
Rob Norris
bca4ca7949