doc: fix spelling of TYPE_get_ex_new_index

The generated macros are TYPE_get_ex_new_index() (to match
CRYPTO_get_ex_new_index()), not TYPE_get_new_ex_index(), even though
the latter spelling seems more natural.
Reviewed-by: NTomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/10943)

(cherry picked from commit fe41c06e69613b1a4814b3e3cdbf460f2678ec99)

doc/man3/BIO_get_ex_new_index.pod

@@ -39,7 +39,7 @@ L<CRYPTO_get_ex_new_index(3)>.
 These functions handle application-specific data for OpenSSL data
 structures.
 
-TYPE_get_new_ex_index() is a macro that calls CRYPTO_get_ex_new_index()
+TYPE_get_ex_new_index() is a macro that calls CRYPTO_get_ex_new_index()
 with the correct B<index> value.
 
 TYPE_set_ex_data() is a function that calls CRYPTO_set_ex_data() with
@@ -50,7 +50,7 @@ an offset into the opaque exdata part of the TYPE object.
 
 =head1 RETURN VALUES
 
-TYPE_get_new_ex_index() returns a new index on success or -1 on error.
+TYPE_get_ex_new_index() returns a new index on success or -1 on error.
 
 TYPE_set_ex_data() returns 1 on success or 0 on error.