mmc: core: Use DEFINE_DEBUGFS_ATTRIBUTE instead of DEFINE_SIMPLE_ATTRIBUTE

Fixes coccicheck warning:

drivers/mmc/core/debugfs.c:222:0-23: WARNING: mmc_clock_fops should be
defined with DEFINE_DEBUGFS_ATTRIBUTE

Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files

Fixes: 703aae3d ("mmc: add a file to debugfs for changing host clock at runtime")
Fixes: a04c50aa ("mmc: core: no need to check return value of debugfs_create functions")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Link: https://lore.kernel.org/r/1587633319-19835-1-git-send-email-zou_wei@huawei.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/debugfs.c

@@ -219,7 +219,7 @@ static int mmc_clock_opt_set(void *data, u64 val)
 	return 0;
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
+DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
 	"%llu\n");
 
 void mmc_add_host_debugfs(struct mmc_host *host)
@@ -232,7 +232,7 @@ void mmc_add_host_debugfs(struct mmc_host *host)
 	debugfs_create_file("ios", S_IRUSR, root, host, &mmc_ios_fops);
 	debugfs_create_x32("caps", S_IRUSR, root, &host->caps);
 	debugfs_create_x32("caps2", S_IRUSR, root, &host->caps2);
-	debugfs_create_file("clock", S_IRUSR | S_IWUSR, root, host,
+	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
 				   &mmc_clock_fops);
 
 #ifdef CONFIG_FAIL_MMC_REQUEST