perf machine: Simplify accessing the host machine

It is always there, no sense in calling a function named
"perf_session__find_host_machine".

Also no sense in checking if that function return is NULL, so ditch
needless error handling.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a6a3zx3afbrxo8p2zqm5mxo8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 0b4b796..9fddca74 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -340,7 +340,7 @@
 			   int n_lines, int is_caller)
 {
 	struct rb_node *next;
-	struct machine *machine;
+	struct machine *machine = &session->machines.host;
 
 	printf("%.102s\n", graph_dotted_line);
 	printf(" %-34s |",  is_caller ? "Callsite": "Alloc Ptr");
@@ -349,11 +349,6 @@
 
 	next = rb_first(root);
 
-	machine = perf_session__find_host_machine(session);
-	if (!machine) {
-		pr_err("__print_result: couldn't find kernel information\n");
-		return;
-	}
 	while (next && n_lines--) {
 		struct alloc_stat *data = rb_entry(next, struct alloc_stat,
 						   node);