kcsan: Remove redundant call of kallsyms_lookup_name()

There is no need to repeatedly call kallsyms_lookup_name, we can reuse
the return value of this function.

Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Signed-off-by: Marco Elver <elver@google.com>

Author: ranxiaokai

kernel/kcsan/debugfs.c

@@ -179,8 +179,7 @@ static ssize_t insert_report_filterlist(const char *func)
 	}
 
 	/* Note: deduplicating should be done in userspace. */
-	report_filterlist.addrs[report_filterlist.used++] =
-		kallsyms_lookup_name(func);
+	report_filterlist.addrs[report_filterlist.used++] = addr;
 	report_filterlist.sorted = false;
 
 	raw_spin_unlock_irqrestore(&report_filterlist_lock, flags);