Rewordings required in logging PEL

This commit rewords some of the comments and variables
in restore VPD PEL code and in vpd-tool restore function.

Eg:
>>Cache value -> Backup value
    [As backup need not be in cache only]
>>Blank data -> Default data
    [As default data need not be blank only]
>>Hardware data -> Primary data
The VPD backup values and backup memory are machine specific.

Thus providing generic terms makes the code statements/comments
more reliable w.r.t any machine.

Signed-off-by: Priyanga Ramasamy <priyanga24@in.ibm.com>
Change-Id: I34fcd44e94b928db0fc30cda94eb8f03e6e87987
diff --git a/const.hpp b/const.hpp
index 5afa3fd..db273e8 100644
--- a/const.hpp
+++ b/const.hpp
@@ -97,10 +97,9 @@
 constexpr auto loggerService = "xyz.openbmc_project.Logging";
 constexpr auto loggerObjectPath = "/xyz/openbmc_project/logging";
 constexpr auto loggerCreateInterface = "xyz.openbmc_project.Logging.Create";
-constexpr auto errIntfForBlankSystemVPD = "com.ibm.VPD.Error.BlankSystemVPD";
+constexpr auto errIntfForVPDDefault = "com.ibm.VPD.Error.DefaultValue";
 constexpr auto errIntfForInvalidVPD = "com.ibm.VPD.Error.InvalidVPD";
-constexpr auto errIntfForSystemVPDMismatch =
-    "com.ibm.VPD.Error.SystemVPDMismatch";
+constexpr auto errIntfForVPDMismatch = "com.ibm.VPD.Error.Mismatch";
 constexpr auto errIntfForStreamFail = "com.ibm.VPD.Error.InavlidEepromPath";
 constexpr auto errIntfForEccCheckFail = "com.ibm.VPD.Error.EccCheckFailed";
 constexpr auto errIntfForJsonFailure = "com.ibm.VPD.Error.InvalidJson";
@@ -115,7 +114,6 @@
 constexpr auto i2cPathPrefix = "/sys/bus/i2c/drivers/at24/";
 constexpr auto spiPathPrefix = "/sys/bus/spi/drivers/at25/";
 constexpr auto invItemIntf = "xyz.openbmc_project.Inventory.Item";
-constexpr auto errIntfForSysVPDMismatch = "com.ibm.VPD.Error.SystemVPDMismatch";
 
 namespace lengths
 {