Fix out-of-date note about AbslStringify CHECK_EQ support

PiperOrigin-RevId: 927016075
Change-Id: I3268d636778c704c01287ceda06d53bed2bcbf3e

absl/log/check.h

diff --git a/absl/log/check.h b/absl/log/check.h
index 9e2219b..10674c9 100644
--- a/absl/log/check.h
+++ b/absl/log/check.h
@@ -102,11 +102,11 @@
 //   Check failed: 2 * x == y (6 vs. 5) oops!
 //
 // The values must implement the appropriate comparison operator as well as
-// `operator<<(std::ostream&, ...)`.  Care is taken to ensure that each
-// argument is evaluated exactly once, and that anything which is legal to pass
-// as a function argument is legal here.  In particular, the arguments may be
-// temporary expressions which will end up being destroyed at the end of the
-// statement,
+// either `operator<<(std::ostream&, ...)` or `AbslStringify`.  Care is taken to
+// ensure that each argument is evaluated exactly once, and that anything which
+// is legal to pass as a function argument is legal here.  In particular, the
+// arguments may be temporary expressions which will end up being destroyed at
+// the end of the statement,
 //
 // Example:
 //