Change provider params from int to size_t

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9699)

test/mdc2test.c

diff --git a/test/mdc2test.c b/test/mdc2test.c
index 5b54f10..d1c2f26 100644
--- a/test/mdc2test.c
+++ b/test/mdc2test.c
@@ -39,7 +39,8 @@
 
 static int test_mdc2(void)
 {
-    int testresult = 0, pad_type = 2;
+    int testresult = 0;
+    unsigned int pad_type = 2;
     unsigned char md[MDC2_DIGEST_LENGTH];
     EVP_MD_CTX *c;
     static char text[] = "Now is the time for all ";
@@ -47,8 +48,8 @@
     OSSL_PROVIDER *prov = NULL;
     OSSL_PARAM params[2];
 
-    params[i++] = OSSL_PARAM_construct_int(OSSL_DIGEST_PARAM_PAD_TYPE,
-                                           &pad_type),
+    params[i++] = OSSL_PARAM_construct_uint(OSSL_DIGEST_PARAM_PAD_TYPE,
+                                            &pad_type),
     params[i++] = OSSL_PARAM_construct_end();
 
     prov = OSSL_PROVIDER_load(NULL, "legacy");