Move duplicate information about the 'zfs send -e' option.

The extra one was under the 'zfs receive' command (which isn't relevant).
Instead, it should have been further up (still in the 'zfs send' option).

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3194