fs/Kconfig: move btrfs out

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

fs/Kconfig

@@ -50,25 +50,7 @@ config FILE_LOCKING
 source "fs/xfs/Kconfig"
 source "fs/gfs2/Kconfig"
 source "fs/ocfs2/Kconfig"
-
-config BTRFS_FS
-	tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
-	depends on EXPERIMENTAL
-	select LIBCRC32C
-	select ZLIB_INFLATE
-	select ZLIB_DEFLATE
-	help
-	  Btrfs is a new filesystem with extents, writable snapshotting,
-	  support for multiple devices and many more features.
-
-	  Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
-	  FINALIZED.  You should say N here unless you are interested in
-	  testing Btrfs with non-critical data.
-
-	  To compile this file system support as a module, choose M here. The
-	  module will be called btrfs.
-
-	  If unsure, say N.
+source "fs/btrfs/Kconfig"
 
 endif # BLOCK
 

fs/btrfs/Kconfig

@@ -0,0 +1,18 @@
+config BTRFS_FS
+	tristate "Btrfs filesystem (EXPERIMENTAL) Unstable disk format"
+	depends on EXPERIMENTAL
+	select LIBCRC32C
+	select ZLIB_INFLATE
+	select ZLIB_DEFLATE
+	help
+	  Btrfs is a new filesystem with extents, writable snapshotting,
+	  support for multiple devices and many more features.
+
+	  Btrfs is highly experimental, and THE DISK FORMAT IS NOT YET
+	  FINALIZED.  You should say N here unless you are interested in
+	  testing Btrfs with non-critical data.
+
+	  To compile this file system support as a module, choose M here. The
+	  module will be called btrfs.
+
+	  If unsure, say N.