tracing: Don't inc err_log entry count if entry allocation fails

tr->n_err_log_entries should only be increased if entry allocation
succeeds.

Doing it when it fails won't cause any problems other than wasting an
entry, but should be fixed anyway.

Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 2f754e77 ("tracing: Don't inc err_log entry count if entry allocation fails")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/trace.c

@@ -7740,7 +7740,8 @@ static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
 		err = kzalloc(sizeof(*err), GFP_KERNEL);
 		if (!err)
 			err = ERR_PTR(-ENOMEM);
-		tr->n_err_log_entries++;
+		else
+			tr->n_err_log_entries++;
 
 		return err;
 	}