In quic_mem_slice_span_test.cc, add a 'u' to a EXPECT_EQ.

gfe-relnote: (n/a) Cosmetic test change.
PiperOrigin-RevId: 240975829
Change-Id: I8d3df95e35fa562de52e51e9b6e2e87defd5802f

quic/platform/api/quic_mem_slice_span_test.cc

diff --git a/quic/platform/api/quic_mem_slice_span_test.cc b/quic/platform/api/quic_mem_slice_span_test.cc
index 067a7a4..8230a1b 100644
--- a/quic/platform/api/quic_mem_slice_span_test.cc
+++ b/quic/platform/api/quic_mem_slice_span_test.cc
@@ -34,7 +34,7 @@
   QuicByteCount bytes_consumed =
       vector.span().ConsumeAll([&](QuicMemSlice slice) {
         EXPECT_EQ(data_, slice.data());
-        EXPECT_EQ(1024, slice.length());
+        EXPECT_EQ(1024u, slice.length());
         ++num_slices;
       });