MSI: fix incorrect return code check

[Mike McCormack]

ChangeLog:
<aric at codeweavers.com>
* fix incorrect return code check
-------------- next part --------------
diff -ur dlls/msi.old/action.c dlls/msi/action.c
--- dlls/msi.old/action.c	2004-12-22 18:43:14.000000000 +0900
+++ dlls/msi/action.c	2004-12-22 18:43:30.000000000 +0900
@@ -658,7 +658,7 @@
         }
 
         check = PACKAGE_GetProperty(package, cszSourceDir);
-        if (check)
+        if (!check)
         {
             MSI_SetPropertyW(package, cszSourceDir, path);
             HeapFree(GetProcessHeap(), 0, check);