NTB: Fix documentation for ntb_link_is_up

There was a copy and paste error in the documentation for
ntb_link_is_up.  The long description was mistakenly copied from
ntb_link_set_trans.

This adds the appropriate long description for ntb_link_is_up.

Reported-by: Dave Jiang <[email protected]>
Signed-off-by: Allen Hubbe <[email protected]>
Signed-off-by: Jon Mason <[email protected]>
1 file changed