perf evlist: Fix type for references to data_head/tail

The data_head and data_tail fields are defined as __u64 in
linux/perf_event.h, but perf userspace uses int and unsigned int.

Convert all references to u64 for consistency.

Signed-off-by: David Ahern <[e-mail]>
Acked-by: Peter Zijlstra <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-record.c

···
 static int record__mmap_read(struct record *rec, int idx)
 {
 	struct perf_mmap *md = &rec->evlist->mmap[idx];
-	unsigned int head = perf_mmap__read_head(md);
-	unsigned int old = md->prev;
+	u64 head = perf_mmap__read_head(md);
+	u64 old = md->prev;
 	unsigned char *data = md->base + page_size;
 	unsigned long size;
 	void *buf;

tools/perf/util/evlist.c

···
 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
 {
 	struct perf_mmap *md = &evlist->mmap[idx];
-	unsigned int head = perf_mmap__read_head(md);
-	unsigned int old = md->prev;
+	u64 head = perf_mmap__read_head(md);
+	u64 old = md->prev;
 	unsigned char *data = md->base + page_size;
 	union perf_event *event = NULL;
 
···
 	struct perf_mmap *md = &evlist->mmap[idx];
 
 	if (!evlist->overwrite) {
-		unsigned int old = md->prev;
+		u64 old = md->prev;
 
 		perf_mmap__write_tail(md, old);
 	}

tools/perf/util/evlist.h

···
 	void		 *base;
 	int		 mask;
 	int		 refcnt;
-	unsigned int	 prev;
+	u64		 prev;
 	char		 event_copy[PERF_SAMPLE_MAX_SIZE] __attribute__((aligned(8)));
 };
 
···
 int perf_evlist__strerror_open(struct perf_evlist *evlist, int err, char *buf, size_t size);
 int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size);
 
-static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm)
+static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
 {
 	struct perf_event_mmap_page *pc = mm->base;
-	int head = ACCESS_ONCE(pc->data_head);
+	u64 head = ACCESS_ONCE(pc->data_head);
 	rmb();
 	return head;
 }
 
-static inline void perf_mmap__write_tail(struct perf_mmap *md,
-					 unsigned long tail)
+static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
 {
 	struct perf_event_mmap_page *pc = md->base;