vdso: don't call close() for a negative value

CID 157801 (#1 of 1): Argument cannot be negative (NEGATIVE_RETURNS)
19. negative_returns: fd is passed to a parameter that cannot be negative.

Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

vdso.c

@@ -212,7 +212,7 @@ int parasite_fixup_vdso(struct parasite_ctl *ctl, pid_t pid,
 	}
 	exit_code = 0;
 err:
-	close(fd);
+	close_safe(&fd);
 	return exit_code;
 }