man find: unify symlink / symbolic link

[積丹尼 Dan Jacobson]

On man find, the only line that talks about "symlinks" is


              %Y File's type (like %y), plus follow symlinks: `L'=loop,
               `N'=nonexistent, `?' for any other error when determining
               the type of the symlink target.

All the many rest on that page call them symbolic links. So this one
should too, else searching for one misses the other, yes even if it is
common knowledge that they are the same.