vfs.zfs.arc_no_grow_shift has an invalid type (15) and this causes
py-sysctl to format it as a bytearray when it should be an integer.
"U" is not a valid format, it should be "I" and the type should match
the variable type, int. We can return EINVAL if the value is set below
zero.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes#11318