user32: Constify some variables

[Andrew Talbot]

Changelog:
    user32: Constify some variables.

diff --git a/dlls/user32/defdlg.c b/dlls/user32/defdlg.c
index 911e0ce..ae9bb9f 100644
--- a/dlls/user32/defdlg.c
+++ b/dlls/user32/defdlg.c
@@ -171,7 +171,7 @@ static BOOL DEFDLG_SetDefId( HWND hwndDlg, DIALOGINFO *dlgInfo, WPARAM wParam)
  *
  * Set the new default button to be hwndNew.
  */
-static BOOL DEFDLG_SetDefButton( HWND hwndDlg, DIALOGINFO *dlgInfo, HWND hwndNew )
+static BOOL DEFDLG_SetDefButton( HWND hwndDlg, const DIALOGINFO *dlgInfo, HWND hwndNew )
 {
     DWORD dlgcode=0; /* initialize just to avoid a warning */
     HWND hwndOld = GetDlgItem( hwndDlg, dlgInfo->idResult );
diff --git a/dlls/user32/defwnd.c b/dlls/user32/defwnd.c
index 2bde5ad..627af47 100644
--- a/dlls/user32/defwnd.c
+++ b/dlls/user32/defwnd.c
@@ -728,7 +728,7 @@ static LRESULT DEFWND_DefWinProc( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lPa
     return 0;
 }
 
-static LPARAM DEFWND_GetTextA( WND *wndPtr, LPSTR dest, WPARAM wParam )
+static LPARAM DEFWND_GetTextA( const WND *wndPtr, LPSTR dest, WPARAM wParam )
 {
     LPARAM result = 0;
 
@@ -875,7 +875,7 @@ LRESULT WINAPI DefWindowProcA( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam
 }
 
 
-static LPARAM DEFWND_GetTextW( WND *wndPtr, LPWSTR dest, WPARAM wParam )
+static LPARAM DEFWND_GetTextW( const WND *wndPtr, LPWSTR dest, WPARAM wParam )
 {
     LPARAM result = 0;
 
diff --git a/dlls/user32/driver16.c b/dlls/user32/driver16.c
index 227742d..be12897 100644
--- a/dlls/user32/driver16.c
+++ b/dlls/user32/driver16.c
@@ -83,7 +83,7 @@ static void DRIVER_LoadStartupDrivers(void)
  *
  * Returns the number of open drivers which share the same module.
  */
-static	WORD	DRIVER_GetNumberOfModuleRefs(LPWINE_DRIVER lpNewDrv)
+static	WORD	DRIVER_GetNumberOfModuleRefs(const WINE_DRIVER *lpNewDrv)
 {
     LPWINE_DRIVER	lpDrv;
     WORD		count = 0;