cmd/protoc-gen-go: update deprecation warning

Change-Id: Ie1a854bf6f47d4ca9e941b6ccc64dc24ff32bd19
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/186657
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/testprotos/benchmarks/benchmarks.pb.go b/internal/testprotos/benchmarks/benchmarks.pb.go
index 220ab24..9c08d4d 100644
--- a/internal/testprotos/benchmarks/benchmarks.pb.go
+++ b/internal/testprotos/benchmarks/benchmarks.pb.go
@@ -70,7 +70,7 @@
 	return mi.MessageOf(x)
 }
 
-// Deprecated: Use BenchmarkDataset.ProtoReflect.Type instead.
+// Deprecated: Use BenchmarkDataset.ProtoReflect.Descriptor instead.
 func (*BenchmarkDataset) Descriptor() ([]byte, []int) {
 	return file_benchmarks_proto_rawDescGZIP(), []int{0}
 }