advapi32: Constify some variables

[Andrew Talbot]

Changelog:
    advapi32: Constify some variables.

diff --git a/dlls/advapi32/cred.c b/dlls/advapi32/cred.c
index e4ea26c..03d7622 100644
--- a/dlls/advapi32/cred.c
+++ b/dlls/advapi32/cred.c
@@ -754,7 +754,7 @@ static BOOL credential_matches_filter(HKEY hkeyCred, LPCWSTR filter)
 
 static DWORD registry_enumerate_credentials(HKEY hkeyMgr, LPCWSTR filter,
                                             LPWSTR target_name,
-                                            DWORD target_name_len, BYTE key_data[KEY_SIZE],
+                                            DWORD target_name_len, const BYTE key_data[KEY_SIZE],
                                             PCREDENTIALW *credentials, char **buffer,
                                             DWORD *len, DWORD *count)
 {
diff --git a/dlls/advapi32/security.c b/dlls/advapi32/security.c
index d86bb1b..2338aca 100644
--- a/dlls/advapi32/security.c
+++ b/dlls/advapi32/security.c
@@ -2735,7 +2735,7 @@ static void split_domain_account( const LSA_UNICODE_STRING *str, LSA_UNICODE_STR
     }
 }
 
-static BOOL match_domain( ULONG idx, LSA_UNICODE_STRING *domain )
+static BOOL match_domain( ULONG idx, const LSA_UNICODE_STRING *domain )
 {
     ULONG len = strlenW( ACCOUNT_SIDS[idx].domain );
 
@@ -2745,7 +2745,7 @@ static BOOL match_domain( ULONG idx, LSA_UNICODE_STRING *domain )
     return FALSE;
 }
 
-static BOOL match_account( ULONG idx, LSA_UNICODE_STRING *account )
+static BOOL match_account( ULONG idx, const LSA_UNICODE_STRING *account )
 {
     ULONG len = strlenW( ACCOUNT_SIDS[idx].account );