net/ulp: Remove redundant ->clone() test in inet_clone_ulp().

Commit 2c02d41d ("net/ulp: prevent ULP without clone op from entering
the LISTEN status") guarantees that all ULP listeners have clone() op, so
we no longer need to test it in inet_clone_ulp().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230217200920.85306-1-kuniyu@amazon.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>