perf callchain: Remove needless event.h include

All we need is a bunch of struct forward declarations and then add
event.h to the only place that was getting it indirectly via
callchain.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-qq2xhyuxcvx5vmxha9otjd8d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/powerpc/util/skip-callchain-idx.c

@@ -13,6 +13,7 @@
 #include "util/callchain.h"
 #include "util/debug.h"
 #include "util/dso.h"
+#include "util/event.h" // struct ip_callchain
 #include "util/map.h"
 #include "util/symbol.h"
 

tools/perf/util/callchain.h

@@ -4,12 +4,15 @@
 
 #include <linux/list.h>
 #include <linux/rbtree.h>
-#include "event.h"
 #include "map_symbol.h"
 #include "branch.h"
 
+struct addr_location;
 struct evsel;
+struct ip_callchain;
 struct map;
+struct perf_sample;
+struct thread;
 
 #define HELP_PAD "\t\t\t\t"
 

tools/perf/util/evsel_fprintf.c

@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include <traceevent/event-parse.h>
 #include "evsel.h"
+#include "util/event.h"
 #include "callchain.h"
 #include "map.h"
 #include "strlist.h"