Fix some man page typos

A few miscellaneous man page typos reported by Hal Murray on
openssl-users.
Reviewed-by: NDmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/12185)

doc/man3/EVP_MAC.pod

@@ -317,12 +317,12 @@ EVP_MAC_do_all_provided() returns nothing at all.
 
       if (cipher != NULL)
           params[params_n++] =
-              OSSL_PARAM_construct_utf8_string("cipher", cipher, 0, NULL);
+              OSSL_PARAM_construct_utf8_string("cipher", cipher, 0;
       if (digest != NULL)
           params[params_n++] =
-              OSSL_PARAM_construct_utf8_string("digest", digest, 0, NULL);
+              OSSL_PARAM_construct_utf8_string("digest", digest, 0);
       params[params_n++] =
-          OSSL_PARAM_construct_octet_string("key", key, strlen(key), NULL);
+          OSSL_PARAM_construct_octet_string("key", key, strlen(key));
       params[params_n] = OSSL_PARAM_construct_end();
 
       if (mac == NULL

doc/man3/EVP_PKEY_CTX_new.pod

@@ -97,7 +97,7 @@ documentation for more information.
 =head1 RETURN VALUES
 
 EVP_PKEY_CTX_new(), EVP_PKEY_CTX_new_id(), EVP_PKEY_CTX_dup() returns either
-the newly allocated B<EVP_PKEY_CTX> structure of B<NULL> if an error occurred.
+the newly allocated B<EVP_PKEY_CTX> structure or B<NULL> if an error occurred.
 
 EVP_PKEY_CTX_free() does not return a value.
 

doc/man3/X509V3_get_d2i.pod

@@ -196,7 +196,7 @@ The following extensions are used by certificate transparency, RFC6962
 =head1 RETURN VALUES
 
 X509V3_EXT_d2i() and *X509V3_get_d2i() return a pointer to an extension
-specific structure of B<NULL> if an error occurs.
+specific structure or B<NULL> if an error occurs.
 
 X509V3_EXT_i2d() returns a pointer to an B<X509_EXTENSION> structure
 or B<NULL> if an error occurs.

doc/man3/X509_NAME_add_entry_by_txt.pod

@@ -81,7 +81,7 @@ X509_NAME_add_entry_by_NID() and X509_NAME_add_entry() return 1 for
 success of 0 if an error occurred.
 
 X509_NAME_delete_entry() returns either the deleted B<X509_NAME_ENTRY>
-structure of B<NULL> if an error occurred.
+structure or B<NULL> if an error occurred.
 
 =head1 EXAMPLES