ossl.c: check integer overflow

* ext/openssl/ossl.c (Init_ossl_locks): check integer overflow.
  OPENSSL_malloc() takes int only.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41879 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ossl.c: check allocation

* ext/openssl/ossl.c (Init_ossl_locks): check if locks array is
  allocated successfully.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41880 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ossl.c: rb_gc_register_mark_object

* ext/openssl/ossl.c (Init_ossl_locks): use rb_gc_register_mark_object
  instead of rb_global_variable.  probably RArray may be used.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41881 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ossl.c: fix argument type

* ext/openssl/ossl.c (ossl_lock_callback): fix argument type, and
  remove redundant casts.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41882 b2dd03c8-39d4-4d8f-98ff-823fe69b080e