Move excpt.h out of include/msvcrt/ as it does not conflict with any
standard Unix header.

diff --git a/dlls/msvcrt/cppexcept.c b/dlls/msvcrt/cppexcept.c
index 23075cc..851e5f1 100644
--- a/dlls/msvcrt/cppexcept.c
+++ b/dlls/msvcrt/cppexcept.c
@@ -29,7 +29,7 @@
 #include "winternl.h"
 #include "msvcrt.h"
 #include "wine/exception.h"
-#include "msvcrt/excpt.h"
+#include "excpt.h"
 #include "wine/debug.h"
 
 WINE_DEFAULT_DEBUG_CHANNEL(seh);