Call EVP_CIPHER_CTX_cleanup to avoid leaking memory that was allocated in EVP_DecryptInit_ex

Also add matching cleanup to EVP_EncryptInit_ex for symmetry (though I'm not
convinced it actually leaks memory)

Change-Id: Icf72dd9e0295d8b6ea55909266a43e684b16420f

cryptfs.c

@@ -1409,6 +1409,8 @@ static int encrypt_master_key(const char *passwd, const unsigned char *salt,
       SLOGE("encrypt_master_key: crypto_scrypt failed");
     }
 
+    EVP_CIPHER_CTX_cleanup(&e_ctx);
+
     return 0;
 }
 
@@ -1458,6 +1460,8 @@ static int decrypt_master_key_aux(const char *passwd, unsigned char *salt,
     }
   }
 
+  EVP_CIPHER_CTX_cleanup(&d_ctx);
+
   return 0;
 }