perf tools: Remove condition in machine__get_kernel_start_addr.

In machine__get_kernel_start_addr, the code, which is using
machine->root_dir to build filename, works for both host and guests
initialized from guestmount, as root_dir is set to "" for the host
machine in the machine__init() function.

So this patch remove the branch for machine__is_host.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/0a81645dd0b384a12cb4f962cf193ef8c3ce2010.1386197481.git.yangds.fnst@cn.fujitsu.com
[ Clarified changeset mentioning root_dir setup in machine__init() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/machine.c

@@ -502,15 +502,11 @@ static u64 machine__get_kernel_start_addr(struct machine *machine)
 	char path[PATH_MAX];
 	struct process_args args;
 
-	if (machine__is_host(machine)) {
-		filename = "/proc/kallsyms";
-	} else {
-		if (machine__is_default_guest(machine))
-			filename = (char *)symbol_conf.default_guest_kallsyms;
-		else {
-			sprintf(path, "%s/proc/kallsyms", machine->root_dir);
-			filename = path;
-		}
+	if (machine__is_default_guest(machine))
+		filename = (char *)symbol_conf.default_guest_kallsyms;
+	else {
+		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
+		filename = path;
 	}
 
 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))