Add errno to CHECK_EQ log

Ignore-AOSP-First: na
Flag: TEST_ONLY
Test: binder_parcel_fuzzer
Bug: 406499223
Change-Id: I67746d7f88c5202c6fa1d43f0b2f0e59bcd10155

Author: devinmoore-goog

libs/binder/tests/parcel_fuzzer/random_fd.cpp

@@ -55,7 +55,8 @@ std::vector<unique_fd> getRandomFds(FuzzedDataProvider* provider) {
                  // TODO(b/236812909): also test blocking
                  if (true) flags |= O_NONBLOCK;
 
-                 CHECK_EQ(0, pipe2(pipefds, flags)) << flags;
+                 CHECK_EQ(0, pipe2(pipefds, flags))
+                         << "flags: " << flags << ", errno: " << strerror(errno);
 
                  if (provider->ConsumeBool()) std::swap(pipefds[0], pipefds[1]);