perf config: Make symbol_conf::addr2line_disable_warn configurable

Make symbol_conf::addr2line_disable_warn configurable by reading
the perfconfig file.
Use section core and addr2line-disable-warn = value.
Update documentation.

Example:
 # perf config -l
 core.addr2line-timeout=5000
 core.addr2line-disable-warn=1
 #

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/Documentation/perf-config.txt

@@ -210,6 +210,12 @@ core.*::
 		Sets a timeout (in milliseconds) for parsing /proc/<pid>/maps files.
 		Can be overridden by the --proc-map-timeout option on supported
 		subcommands. The default timeout is 500ms.
+	addr2line-disable-warn::
+		When set to 'true' disable all warnings from 'addr2line' output.
+		Default setting is 'false' to show these warnings.
+	addr2line-timeout::
+		Sets a timeout (in milliseconds) for parsing 'addr2line'
+		output.  The default timeout is 5s.
 
 tui.*, gtk.*::
 	Subcommands that can be configured here are 'top', 'report' and 'annotate'.

tools/perf/util/config.c

@@ -461,6 +461,9 @@ static int perf_default_core_config(const char *var, const char *value)
 	if (!strcmp(var, "core.addr2line-timeout"))
 		addr2line_timeout_ms = strtoul(value, NULL, 10);
 
+	if (!strcmp(var, "core.addr2line-disable-warn"))
+		symbol_conf.addr2line_disable_warn = perf_config_bool(var, value);
+
 	/* Add other config variables here. */
 	return 0;
 }