Silence a crash in update_engine when dns resolution fails

Summary: This change silence below crash. It occurs in certain
conditions when a connection fails while it is paused

Error:
SIGABRT:/system/bin/update_engine::chromeos_update_engine::(anonymous
namespace)::RedirectToLiblog(int, char const*, int, unsigned long, std::

Test: build passes
Change-Id: I7b38c354d2a5d484b993944a14c8c2da56cf9650
Signed-off-by: Abhishek Gadewar <abhishekgadewar@meta.com>
diff --git a/libcurl_http_fetcher.cc b/libcurl_http_fetcher.cc
index 08c8a67..db94a6f 100644
--- a/libcurl_http_fetcher.cc
+++ b/libcurl_http_fetcher.cc
@@ -648,11 +648,17 @@
     return;
   }
   CHECK(curl_handle_);
-  CHECK_EQ(curl_easy_pause(curl_handle_, CURLPAUSE_CONT), CURLE_OK);
-  // Since the transfer is in progress, we need to dispatch a CurlPerformOnce()
-  // now to let the connection continue, otherwise it would be called by the
-  // TimeoutCallback but with a delay.
-  CurlPerformOnce();
+  auto ret = curl_easy_pause(curl_handle_, CURLPAUSE_CONT);
+  if (ret != CURLE_OK) {
+    LOG(ERROR) << "Failed to unpause connection, reason: " << ret
+               << ". Terminating transfer.";
+    TerminateTransfer();
+  } else {
+    // Since the transfer is in progress, we need to dispatch a
+    // CurlPerformOnce() now to let the connection continue, otherwise it would
+    // be called by the TimeoutCallback but with a delay.
+    CurlPerformOnce();
+  }
 }
 
 // This method sets up callbacks with the MessageLoop.