Remove stale comment

Change-Id: I008ba23229804bf025243869042227e56f18a284
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/82127
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>

crypto/rand/urandom.cc

diff --git a/crypto/rand/urandom.cc b/crypto/rand/urandom.cc
index 6fa393e..d1eed69 100644
--- a/crypto/rand/urandom.cc
+++ b/crypto/rand/urandom.cc
@@ -158,12 +158,6 @@
 #endif  // USE_NR_getrandom
 
   // FIPS builds must support getrandom.
-  //
-  // Historically, only Android FIPS builds required getrandom, while Linux FIPS
-  // builds had a /dev/urandom fallback which used RNDGETENTCNT as a poor
-  // approximation for getrandom's blocking behavior. This is now removed, but
-  // avoid making assumptions on this removal until March 2023, in case it needs
-  // to be restored. This comment can be deleted after March 2023.
 #if defined(BORINGSSL_FIPS)
   perror("getrandom not found");
   abort();