scripts/coccinelle: ptr_ret: Add ternary operator version

Add a ternary operator version of the open-coded PTR_RET().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>