Fix problems found by Coverity.

longobject.c: also fix an ssize_t problem
  <a> could have been NULL, so hoist the size calc to not use <a>.

_ssl.c: under fail: self is DECREF'd, but it would have been NULL.

_elementtree.c: delete self if there was an error.

_csv.c: I'm not sure if lineterminator could have been anything other than
a string.  However, other string method calls are checked, so check this
one too.
diff --git a/Modules/_csv.c b/Modules/_csv.c
index 67d5d9f..5e03635 100644
--- a/Modules/_csv.c
+++ b/Modules/_csv.c
@@ -1104,6 +1104,8 @@
 	char *terminator;
 
 	terminator_len = PyString_Size(self->dialect->lineterminator);
+	if (terminator_len == -1)
+		return 0;
 
 	/* grow record buffer if necessary */
 	if (!join_check_rec_size(self, self->rec_len + terminator_len))