Get rid of a warning in twain

[Vincent Béron <vberon@xxxxxxxxxxxxxxxxxxxx>]

Not sure why this was in a comment, similar functions around this one
are fully operational.

Changelog:
Initialize a pointer before dereferencing it in twain.

Vincent

Index: dlls/twain/dsm_ctrl.c
===================================================================
RCS file: /home/wine/wine/dlls/twain/dsm_ctrl.c,v
retrieving revision 1.6
diff -u -r1.6 dsm_ctrl.c
--- dlls/twain/dsm_ctrl.c	22 Aug 2003 05:05:56 -0000	1.6
+++ dlls/twain/dsm_ctrl.c	15 Jan 2004 14:40:47 -0000
@@ -136,7 +136,7 @@
     return TWRC_FAILURE;
 #else
     TW_UINT16 twRC = TWRC_SUCCESS;
-    pTW_IDENTITY pSourceIdentity;/* = (pTW_IDENTITY) pData;*/
+    pTW_IDENTITY pSourceIdentity = (pTW_IDENTITY) pData;
     SANE_Status status;
 
     TRACE ("DG_CONTROL/DAT_IDENTITY/MSG_GETFIRST\n");