doc: correcting the debug path for cachefiles

The original debug path is under "/sys/modules", that's
wrong. The real path in kernel is "/sys/module". So we
can correct it.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Link: https://lore.kernel.org/r/20241022013812.2880883-1-lihongbo22@huawei.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: Hongbo Li

Documentation/filesystems/caching/cachefiles.rst

@@ -115,7 +115,7 @@ set up cache ready for use.  The following script commands are available:
 
 	This mask can also be set through sysfs, eg::
 
-		echo 5 >/sys/modules/cachefiles/parameters/debug
+		echo 5 > /sys/module/cachefiles/parameters/debug
 
 
 Starting the Cache