bcachefs: Remove obsolete comment about zstd

Remove obsolete comment about zstd, since approach changed during
development of commit bbc3a460Signed-off-by: Richard Davies <richard@arachsys.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/compress.c

@@ -572,10 +572,6 @@ static int __bch2_fs_compress_init(struct bch_fs *c, u64 features)
 	ZSTD_parameters params = zstd_get_params(zstd_max_clevel(),
 						 c->opts.encoded_extent_max);
 
-	/*
-	 * ZSTD is lying: if we allocate the size of the workspace it says it
-	 * requires, it returns memory allocation errors
-	 */
 	c->zstd_workspace_size = zstd_cctx_workspace_bound(&params.cParams);
 
 	struct {