netfs: clean up after renaming FSCACHE_DEBUG config

Commit 6b8e61472529 ("netfs: Rename CONFIG_FSCACHE_DEBUG to
CONFIG_NETFS_DEBUG") renames the config, but introduces two issues: First,
NETFS_DEBUG mistakenly depends on the non-existing config NETFS, whereas
the actual intended config is called NETFS_SUPPORT. Second, the config
renaming misses to adjust the documentation of the functionality of this
config.

Clean up those two points.

Signed-off-by: Lukas Bulwahn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Christian Brauner <[e-mail]>

Documentation/filesystems/caching/fscache.rst

···
 Debugging
 =========
 
-If CONFIG_FSCACHE_DEBUG is enabled, the FS-Cache facility can have runtime
-debugging enabled by adjusting the value in::
+If CONFIG_NETFS_DEBUG is enabled, the FS-Cache facility and NETFS support can
+have runtime debugging enabled by adjusting the value in::
 
-	/sys/module/fscache/parameters/debug
+	/sys/module/netfs/parameters/debug
 
 This is a bitmask of debugging streams to enable:
 
···
 The appropriate set of values should be OR'd together and the result written to
 the control file.  For example::
 
-	echo $((1|8|512)) >/sys/module/fscache/parameters/debug
+	echo $((1|8|512)) >/sys/module/netfs/parameters/debug
 
 will turn on all function entry debugging.

fs/netfs/Kconfig

···
 
 config NETFS_DEBUG
 	bool "Enable dynamic debugging netfslib and FS-Cache"
-	depends on NETFS
+	depends on NETFS_SUPPORT
 	help
 	  This permits debugging to be dynamically enabled in the local caching
 	  management module.  If this is set, the debugging output may be