compel: Define __sys_err-s for scm stuff

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

compel/plugins/std/fds.c

@@ -15,6 +15,7 @@
 #include "common/bug.h"
 
 #define __sys(foo)	sys_##foo
+#define __sys_err(ret)	ret
 #define __memcpy	std_memcpy
 
 #include "common/scm-code.c"

compel/src/lib/infect.c

@@ -30,6 +30,7 @@
 #include "infect-util.h"
 
 #define __sys(foo)	foo
+#define __sys_err(ret)	(-errno)
 #define __memcpy	memcpy
 
 #include "common/scm.h"