user: Remove superfluous shadow variable

[Andrew Talbot]

Changelog:
    user: Remove superfluous shadow variable.

diff -urN a/dlls/user/dde_client.c b/dlls/user/dde_client.c
--- a/dlls/user/dde_client.c	2006-10-20 18:08:05.000000000 +0100
+++ b/dlls/user/dde_client.c	2006-10-23 22:45:41.000000000 +0100
@@ -1035,7 +1035,6 @@
 
 	    while (PeekMessageW(&msg, 0, WM_DDE_FIRST, WM_DDE_LAST, PM_REMOVE))
 	    {
-                WDML_CONV *pConv;
                 HDDEDATA hdd;
 
                 EnterCriticalSection(&WDML_CritSect);