global cleanup to use the new syscall interface

src/linux/sendfile.c

@@ -4,7 +4,7 @@
 
 ssize_t sendfile(int out_fd, int in_fd, off_t *ofs, size_t count)
 {
-	return syscall4(__NR_sendfile, out_fd, in_fd, (long)ofs, count);
+	return syscall(SYS_sendfile, out_fd, in_fd, ofs, count);
 }
 
 LFS64(sendfile);