Fix __stdcall placement and function prototype

MSVC requires __stdcall to be between the functions return value and the
function name, and that the function pointer type is in the form of

    return_type (WINAPI *function_name)(arguments...)

Signed-off-by: Frank Li <lznuaa@gmail.com>
Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

run-command.c

@@ -316,7 +316,7 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const
 }
 
 #ifdef __MINGW32__
-static __stdcall unsigned run_thread(void *data)
+static unsigned __stdcall run_thread(void *data)
 {
 	struct async *async = data;
 	return async->proc(async->fd_for_proc, async->data);