fix comments in experimental/crypto/Blake2xb.h

Summary: The reinit() method was removed but some comments mentioning it remained. Remove them.

Reviewed By: yfeldblum

Differential Revision: D14277614

fbshipit-source-id: 389ef3e2afe1fdc60f37aaec2f8a48dfa0b1436c

folly/experimental/crypto/Blake2xb.h

@@ -71,7 +71,7 @@ class Blake2xb {
   static constexpr size_t kMaxOutputLength = 0xfffffffeULL;
   /**
    * If the amount of output data desired is not known in advance, use this
-   * constant as the outputLength parameter to init() or reinit().
+   * constant as the outputLength parameter to init().
    */
   static constexpr size_t kUnknownOutputLength = 0;
 
@@ -116,7 +116,7 @@ class Blake2xb {
   /**
    * Computes the final hash and stores it in the given output. The value of
    * out.size() MUST equal the outputLength parameter that was given to the
-   * last init() or reinit() call, except when the outputLength parameter was
+   * last init() call, except when the outputLength parameter was
    * kUnknownOutputLength.
    *
    * WARNING: never compare the results of two Blake2xb.finish() calls