Rename OPENSSL_CTX prefix to OSSL_LIB_CTX

Many of the new types introduced by OpenSSL 3.0 have an OSSL_ prefix,
e.g., OSSL_CALLBACK, OSSL_PARAM, OSSL_ALGORITHM, OSSL_SERIALIZER.

The OPENSSL_CTX type stands out a little by using a different prefix.
For consistency reasons, this type is renamed to OSSL_LIB_CTX.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/12621)
diff --git a/test/provider_status_test.c b/test/provider_status_test.c
index 83572e8..fb52fa6 100644
--- a/test/provider_status_test.c
+++ b/test/provider_status_test.c
@@ -28,7 +28,7 @@
     int count;
 };
 
-static OPENSSL_CTX *libctx = NULL;
+static OSSL_LIB_CTX *libctx = NULL;
 static char *provider_name = NULL;
 static struct self_test_arg self_test_args = { 0 };
 
@@ -170,13 +170,13 @@
         }
     }
 
-    libctx = OPENSSL_CTX_new();
+    libctx = OSSL_LIB_CTX_new();
     if (libctx == NULL)
         return 0;
     self_test_args.count = 0;
     OSSL_SELF_TEST_set_callback(libctx, self_test_on_load, &self_test_args);
 
-    if (!OPENSSL_CTX_load_config(libctx, config_file)) {
+    if (!OSSL_LIB_CTX_load_config(libctx, config_file)) {
         opt_printf_stderr("Failed to load config\n");
         return 0;
     }