perf ui: Reimplement the popup windows using libslang

Just another step in stopping the use of libnewt in perf.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
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-vtxnmz1t1807ykprapnk9njl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index bc8f477..119e996 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -310,9 +310,12 @@
 		}
 		err = -ENOENT;
 		dso->annotate_warned = 1;
-		pr_err("Can't annotate %s: No vmlinux file%s was found in the "
-		       "path.\nPlease use 'perf buildid-cache -av vmlinux' or "
-		       "--vmlinux vmlinux.\n",
+		pr_err("Can't annotate %s:\n\n"
+		       "No vmlinux file%s\nwas found in the path.\n\n"
+		       "Please use:\n\n"
+		       "  perf buildid-cache -av vmlinux\n\n"
+		       "or:\n\n"
+		       "  --vmlinux vmlinux",
 		       sym->name, build_id_msg ?: "");
 		goto out_free_filename;
 	}