crypto: Clean up help text for CRYPTO_BLAKE2B

Btrfs stopped using this BLAKE2b implementation in commit
fe11ac1 ("btrfs: switch to library APIs for checksums").

Signed-off-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/98b983d2f2bddf0e5e8e1c970446c3c64527ef89.1772116160.git.geert+renesas@glider.be
Signed-off-by: Eric Biggers <[email protected]>

Author: geertu

crypto/Kconfig

@@ -876,8 +876,6 @@ config CRYPTO_BLAKE2B
 	  - blake2b-384
 	  - blake2b-512
 
-	  Used by the btrfs filesystem.
-
 	  See https://blake2.net for further information.
 
 config CRYPTO_CMAC