sctp: fix memleak on err handling of stream initialization

sctp: fix memleak on err handling of stream initialization

syzbot reported a memory leak when an allocation fails within
genradix_prealloc() for output streams. That's because
genradix_prealloc() leaves initialized members initialized when the
issue happens and SCTP stack will abort the current initialization but
without cleaning up such members.

The fix here is to always call genradix_free() when genradix_prealloc()
fails, for output and also input streams, as it suffers from the same
issue.

Reported-by: [email protected]
Fixes: 2075e50caf5e ("sctp: convert to genradix")
Signed-off-by: Marcelo Ricardo Leitner <[email protected]>
Tested-by: Xin Long <[email protected]>
Signed-off-by: David S. Miller <[email protected]>