SWDEV-477584 - hipExtGetLastError should return the immediate previous API error

hipGetLastError should return the error by any of the previous APIs
in the same host thread to match the CUDA behavior, whereas
hipExtGetLastError will return the error by the immediate previous API.
This Ext API was added earlier to facilitate the existing HIP apps which
are following the current behavior of hipGetLastError

Change-Id: I61e95b1fc136cc761e2434e02187b7ed2598b733

hipamd/src/hip_error.cpp

@@ -26,8 +26,8 @@ namespace hip {
 hipError_t hipExtGetLastError()
 {
   HIP_INIT_API(hipExtGetLastError);
-  hipError_t err = hip::tls.last_error_;
-  hip::tls.last_error_ = hipSuccess;
+  hipError_t err = hip::tls.last_command_error_;
+  hip::tls.last_command_error_ = hipSuccess;
   return err;
 }