Fix cppcheck warnings

This patch fixes the following cppcheck issues:

git/src/argument.cpp:52:35:
  Parameter 'argv' can be const. [constParameter]

git/src/ncsi_util.hpp:104,105,158,159:
  Missing 'override' on virtuals. [missingOverride]

git/src/ncsi_util.cpp:387:33:
  C-style cast used. [cstyleCast]

git/src/ncsi_util.cpp:654:26:
  'respPayload' not assigned. [unassignedVariable]

static_gateway.cpp:17:60:
  Param 'addr' should be const ref. [passedByValue]

Change-Id: Icb96e9fb891512924febef48b09aaf291a50add1
Signed-off-by: Rashid MP <rashidmp@ami.com>
diff --git a/src/ncsi_util.cpp b/src/ncsi_util.cpp
index b8a340d..c612db1 100644
--- a/src/ncsi_util.cpp
+++ b/src/ncsi_util.cpp
@@ -384,7 +384,7 @@
     {
         std::vector<unsigned char> pl(
             sizeof(NCSIPacketHeader) + cmd.payload.size());
-        NCSIPacketHeader* hdr = (NCSIPacketHeader*)pl.data();
+        NCSIPacketHeader* hdr = reinterpret_cast<NCSIPacketHeader*>(pl.data());
 
         std::copy(cmd.payload.begin(), cmd.payload.end(),
                   pl.begin() + sizeof(NCSIPacketHeader));
@@ -651,7 +651,7 @@
     }
 
     internal::NCSIPacketHeader* respHeader;
-    NCSIResponsePayload* respPayload;
+    NCSIResponsePayload* respPayload = nullptr;
     NCSIResponse resp{};
 
     resp.full_payload.resize(maxRespLen);