external/boringssl: Sync to f21650709a6f76e829ddcc77fe221c9d6a5c12de.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/348f0d8db9c2a0eca0503ba654020209c579d552..f21650709a6f76e829ddcc77fe221c9d6a5c12de

Test: BoringSSL CTS Presubmits.
Change-Id: Ie6e99c3315c552068b5ea57e31b1af7ff94f9b0f
diff --git a/src/decrepit/macros.h b/src/decrepit/macros.h
index 228183a..6c598d4 100644
--- a/src/decrepit/macros.h
+++ b/src/decrepit/macros.h
@@ -58,7 +58,7 @@
 #define OPENSSL_HEADER_DECREPIT_MACROS_H
 
 
-/* NOTE - c is not incremented as per n2l */
+// NOTE - c is not incremented as per n2l
 #define n2ln(c, l1, l2, n)                       \
   {                                              \
     c += n;                                      \
@@ -83,7 +83,7 @@
     }                                            \
   }
 
-/* NOTE - c is not incremented as per l2n */
+// NOTE - c is not incremented as per l2n
 #define l2nn(l1, l2, c, n)                               \
   {                                                      \
     c += n;                                              \
@@ -120,4 +120,4 @@
    l |= ((unsigned long)(*((c)++))))
 
 
-#endif  /* OPENSSL_HEADER_DECREPIT_MACROS_H */
+#endif  // OPENSSL_HEADER_DECREPIT_MACROS_H