config.h.in: use const variables instead of macros

Most style guides try to avoid preprocessor macros, especially the use
case here: const objects. This change replaced them with const
variables. Their names are also changed according to the OpenBMC style
guide.

Reference:
https://google.github.io/styleguide/cppguide.html#Preprocessor_Macros

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: I0786c7c83f3a0d892c14f1cb813d0aa16d627b3e
diff --git a/certs_manager.cpp b/certs_manager.cpp
index ed6e375..9adca20 100644
--- a/certs_manager.cpp
+++ b/certs_manager.cpp
@@ -155,7 +155,7 @@
         elog<NotAllowed>(Reason("Certificate already exist"));
     }
     else if (certType == phosphor::certs::AUTHORITY &&
-             installedCerts.size() >= AUTHORITY_CERTIFICATES_LIMIT)
+             installedCerts.size() >= maxNumAuthorityCertificates)
     {
         elog<NotAllowed>(Reason("Certificates limit reached"));
     }
@@ -418,7 +418,7 @@
     }
 
     // Write private key to file
-    writePrivateKey(pKey, PRIV_KEY_FILE_NAME);
+    writePrivateKey(pKey, defaultPrivateKeyFileName);
 
     // set sign key of x509 req
     ret = X509_REQ_sign(x509Req.get(), pKey.get(), EVP_sha256());
@@ -429,7 +429,7 @@
     }
 
     log<level::INFO>("Writing CSR to file");
-    fs::path csrFilePath = certParentInstallPath / CSR_FILE_NAME;
+    fs::path csrFilePath = certParentInstallPath / defaultCSRFileName;
     writeCSR(csrFilePath.string(), x509Req);
 }
 
@@ -778,14 +778,14 @@
 void Manager::createRSAPrivateKeyFile()
 {
     fs::path rsaPrivateKeyFileName =
-        certParentInstallPath / RSA_PRIV_KEY_FILE_NAME;
+        certParentInstallPath / defaultRSAPrivateKeyFileName;
 
     try
     {
         if (!fs::exists(rsaPrivateKeyFileName))
         {
             writePrivateKey(generateRSAKeyPair(SUPPORTED_KEYBITLENGTH),
-                            RSA_PRIV_KEY_FILE_NAME);
+                            defaultRSAPrivateKeyFileName);
         }
     }
     catch (const InternalFailure& e)
@@ -807,7 +807,7 @@
             Argument::ARGUMENT_VALUE(std::to_string(keyBitLength).c_str()));
     }
     fs::path rsaPrivateKeyFileName =
-        certParentInstallPath / RSA_PRIV_KEY_FILE_NAME;
+        certParentInstallPath / defaultRSAPrivateKeyFileName;
 
     FILE* privateKeyFile = std::fopen(rsaPrivateKeyFileName.c_str(), "r");
     if (!privateKeyFile)