perf config: Fix an error in the config template documentation

The option 'sort-order' should be 'sort_order'.

Signed-off-by: Changbin Du <[e-mail]>
Reviewed-by: Jiri Olsa <[e-mail]>
Cc: Alexei Starovoitov <[e-mail]>
Cc: Daniel Borkmann <[e-mail]>
Cc: Milian Wolff <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Steven Rostedt (VMware) <[e-mail]>
Fixes: 893c5c798be9 ("perf config: Show default report configuration in example and docs")
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Documentation/perf-config.txt

···
 
 	[report]
 		# Defaults
-		sort-order = comm,dso,symbol
+		sort_order = comm,dso,symbol
 		percent-limit = 0
 		queue-size = 0
 		children = true