Rename pr_error to err_name in the nss log added in r259205.

net/socket/nss_ssl_util.cc

Index: net/socket/nss_ssl_util.cc
diff --git a/net/socket/nss_ssl_util.cc b/net/socket/nss_ssl_util.cc
index 4811e46f3934ed701f25b91c08769c2c090485cf..7b068545a55290b6368816a992cca3f7161d720e 100644
--- a/net/socket/nss_ssl_util.cc
+++ b/net/socket/nss_ssl_util.cc
@@ -357,15 +357,15 @@ int MapNSSError(PRErrorCode err) {
       return ERR_SSL_INAPPROPRIATE_FALLBACK;
 
     default: {
-      const char* pr_error = PR_ErrorToName(err);
-      if (pr_error == NULL)
-        pr_error = "";
+      const char* err_name = PR_ErrorToName(err);
+      if (err_name == NULL)
+        err_name = "";
       if (IS_SSL_ERROR(err)) {
-        LOG(WARNING) << "Unknown SSL error " << err << " (" << pr_error << ")"
+        LOG(WARNING) << "Unknown SSL error " << err << " (" << err_name << ")"
                      << " mapped to net::ERR_SSL_PROTOCOL_ERROR";
         return ERR_SSL_PROTOCOL_ERROR;
       }
-      LOG(WARNING) << "Unknown error " << err << " (" << pr_error << ")"
+      LOG(WARNING) << "Unknown error " << err << " (" << err_name << ")"
                    << " mapped to net::ERR_FAILED";
       return ERR_FAILED;
     }