trace-cmd listen: Replace tab with spaces in help output

The bash completions of trace-cmd commands uses the -h to find the options
to finish the completions with. trace-cmd listen -h had a tab before "-l"
which caused the completions to miss it. Not to mention, it caused -l not to
be in line with the other options.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/trace-usage.c b/trace-usage.c
index 9664aa6..5b314a6 100644
--- a/trace-usage.c
+++ b/trace-usage.c
@@ -226,7 +226,7 @@
 		"          -D create it in daemon mode.\n"
 		"          -o file name to use for clients.\n"
 		"          -d diretory to store client files.\n"
-		"	   -l logfile to write messages to.\n"
+		"          -l logfile to write messages to.\n"
 	},
 	{
 		"list",