[test] remove a special test case (#331)

Author: ahorek

src/test/ruby/test_cipher.rb

@@ -470,23 +470,19 @@ def test_encrypt_aes_cfb_20_incompatibility
 
   def test_encrypt_aes_256_cbc_modifies_buffer
     cipher = OpenSSL::Cipher.new("AES-256-CBC")
-    cipher.key = "a" * 32
     cipher.encrypt
+    cipher.key = "a" * 32
     buffer = ''
     actual = cipher.update('bar' * 10, buffer)
-    if jruby?
-      expected = "\xE6\xD3Y\fc\xEE\xBA\xB2*\x0Fr\xD1\xC2b\x03\xD0"
-    else
-      expected = "8\xA7\xBE\xB1\xAE\x88j\xCB\xA3\xE9j\x00\xD2W_\x91"
-    end
+    expected = "\xE6\xD3Y\fc\xEE\xBA\xB2*\x0Fr\xD1\xC2b\x03\xD0"
     assert_equal actual, expected
     assert_equal buffer, expected
   end
 
   def test_encrypt_aes_256_cbc_invalid_buffer
     cipher = OpenSSL::Cipher.new("AES-256-CBC")
-    cipher.key = "a" * 32
     cipher.encrypt
+    cipher.key = "a" * 32
     buffer = Object.new
     assert_raise(TypeError) { cipher.update('bar' * 10, buffer) }
   end