fix another error caused by the uapi and libc headers mixup

print_epoll_data() expects epoll_event.data to be a union, but the
bundled/uapi linux/eventpoll.h defines it as a __u64 int.

on android, that union is defined in bits/epoll_event.h which is
included from sys/epoll.h via linux/eventpoll.h, but the bundled
linux/eventpoll.h shadows it, and so src/epoll.c ends up with the
uapi definition of 'struct epoll_event' and no definition at all
of the epoll_data_t union.

use a kludge to continue printing the u64 .data as a structure made up
of a u32 and a u64 field -- which was quite dumb in the first place,
but I guess they have tests checking for that *exact* output.

src/epoll.c

@@ -10,7 +10,7 @@
 
 #include "defs.h"
 #include "kernel_fcntl.h"
-#include <sys/epoll.h>
+#include <linux/eventpoll.h>
 
 SYS_FUNC(epoll_create)
 {
@@ -34,16 +34,17 @@ SYS_FUNC(epoll_create1)
 #include "xlat/epollevents.h"
 
 static void
-print_epoll_data(const epoll_data_t data)
+print_epoll_data(const __u64 data)
 {
 	/*
 	 * We cannot know what format the tracee uses, so
-	 * print both u32 and u66 which will cover every value.
+	 * print both u32 and u64 which will cover every value.
 	 */
+	union dummy { __u64 u64; __u32 u32; } u; u.u64 = data;
 	tprint_struct_begin();
-	PRINT_FIELD_U(data, u32);
+	PRINT_FIELD_U(u, u32);
 	tprint_struct_next();
-	PRINT_FIELD_U(data, u64);
+	PRINT_FIELD_U(u, u64);
 	tprint_struct_end();
 }