REST: Fixed issues with rest POST method

Fixes the below issues in rest actions
 - Fetching dbus signature from xml arg elements.
 - Double iterator increament, while reading array
   of strings 'as'.

Test:
Verified rest API's with actions(POST).

Change-Id: I52ca938bae54c882da2f9f445ea0b4e605a5f8c3
Signed-off-by: AppaRao Puli <apparao.puli@linux.intel.com>
diff --git a/include/openbmc_dbus_rest.hpp b/include/openbmc_dbus_rest.hpp
index c3908ca..fe85d65 100644
--- a/include/openbmc_dbus_rest.hpp
+++ b/include/openbmc_dbus_rest.hpp
@@ -652,8 +652,6 @@
                 {
                     return r;
                 }
-
-                it++;
             }
             sd_bus_message_close_container(m);
         }
@@ -830,7 +828,6 @@
                                         argType != nullptr &&
                                         std::string(argDirection) == "in")
                                     {
-
                                         if (argIt ==
                                             transaction->arguments.end())
                                         {
@@ -850,7 +847,7 @@
                                         argIt++;
                                     }
                                     argumentNode =
-                                        methodNode->NextSiblingElement("arg");
+                                        argumentNode->NextSiblingElement("arg");
                                 }
 
                                 crow::connections::systemBus->async_send(