AMD64 has a single MS-Win calling convention, so provide an empty __stdcall.

Centralize the definition to make it easier to change.

sys/compat/ndis/kern_ndis.c

@@ -75,7 +75,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/ndis/cfg_var.h>
 #include <dev/if_ndis/if_ndisvar.h>
 
-#define __stdcall __attribute__((__stdcall__))
 #define NDIS_DUMMY_PATH "\\\\some\\bogus\\path"
 
 __stdcall static void ndis_status_func(ndis_handle, ndis_status,

sys/compat/ndis/pe_var.h

@@ -408,6 +408,20 @@ struct image_patch_table {
 
 typedef struct image_patch_table image_patch_table;
 
+/*
+ * Note: Windows uses the _stdcall calling convention. This means
+ * that the callback functions provided in the function table must
+ * be declared using __attribute__((__stdcall__)), otherwise the
+ * Windows code will likely screw up the %esp register and cause
+ * us to jump to an invalid address when it returns.
+ */
+
+#ifdef __amd64__
+#define __stdcall
+#else
+#define __stdcall __attribute__((__stdcall__))
+#endif
+
 __BEGIN_DECLS
 extern int pe_get_dos_header(vm_offset_t, image_dos_header *);
 extern int pe_is_nt_image(vm_offset_t);

sys/compat/ndis/subr_hal.c

@@ -55,11 +55,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/ndis/hal_var.h>
 #include <compat/ndis/ntoskrnl_var.h>
 
-#ifdef __amd64__
-#define __stdcall
-#else
-#define __stdcall __attribute__((__stdcall__))
-#endif
 #define FUNC void(*)(void)
 
 __stdcall static void hal_stall_exec_cpu(uint32_t);

sys/compat/ndis/subr_ndis.c

@@ -100,7 +100,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/ndis/cfg_var.h>
 #include <dev/if_ndis/if_ndisvar.h>
 
-#define __stdcall __attribute__((__stdcall__))
 #define FUNC void(*)(void)
 
 static struct mtx *ndis_interlock;

sys/compat/ndis/subr_ntoskrnl.c

@@ -60,7 +60,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/ndis/ndis_var.h>
 #include <compat/ndis/ntoskrnl_var.h>
 
-#define __stdcall __attribute__((__stdcall__))
 #define __regparm __attribute__((regparm(3)))
 
 #define FUNC void(*)(void)

sys/compat/ndis/subr_pe.c

@@ -575,12 +575,6 @@ pe_functbl_match(functbl, name)
  * Note that there are actually two copies of the jump table: one
  * copy is left alone. In a .SYS file, the jump tables are usually
  * merged into the INIT segment.
- *
- * Note: Windows uses the _stdcall calling convention. This means
- * that the callback functions provided in the function table must
- * be declared using __attribute__((__stdcall__)), otherwise the
- * Windows code will likely screw up the %esp register and cause
- * us to jump to an invalid address when it returns.
  */
 
 int