provider: use #define for PBKDF1 algorithm name

This seems to be standard practice so bringing PBKDF1 into line.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from openssl#15967)

Author: paulidale

providers/implementations/include/prov/names.h

@@ -250,6 +250,7 @@
 #define PROV_NAMES_HKDF "HKDF"
 #define PROV_DESCS_HKDF_SIGN "OpenSSL HKDF via EVP_PKEY implementation"
 #define PROV_NAMES_SSKDF "SSKDF"
+#define PROV_NAMES_PBKDF1 "PBKDF1"
 #define PROV_NAMES_PBKDF2 "PBKDF2:1.2.840.113549.1.5.12"
 #define PROV_NAMES_SSHKDF "SSHKDF"
 #define PROV_NAMES_X963KDF "X963KDF:X942KDF-CONCAT"

providers/legacyprov.c

@@ -144,7 +144,7 @@ static const OSSL_ALGORITHM legacy_ciphers[] = {
 };
 
 static const OSSL_ALGORITHM legacy_kdfs[] = {
-    ALG("PBKDF1", ossl_kdf_pbkdf1_functions),
+    ALG(PROV_NAMES_PBKDF1, ossl_kdf_pbkdf1_functions),
     { NULL, NULL, NULL }
 };