[rcp] fix transaction ID caching and guard max power table code (#8408)

- Separate out max power table related code.
- Cache the transaction ID for async response only if
  otLinkRawTransmit() succeeds.

src/lib/spinel/radio_spinel_impl.hpp

@@ -2388,6 +2388,7 @@ void RadioSpinel<InterfaceType, ProcessContextType>::RestoreProperties(void)
         SuccessOrDie(Set(SPINEL_PROP_PHY_FEM_LNA_GAIN, SPINEL_DATATYPE_INT8_S, mFemLnaGain));
     }
 
+#if OPENTHREAD_POSIX_CONFIG_MAX_POWER_TABLE_ENABLE
     for (uint8_t channel = Radio::kChannelMin; channel <= Radio::kChannelMax; channel++)
     {
         int8_t power = mMaxPowerTable.GetTransmitPower(channel);
@@ -2403,6 +2404,7 @@ void RadioSpinel<InterfaceType, ProcessContextType>::RestoreProperties(void)
             }
         }
     }
+#endif // OPENTHREAD_POSIX_CONFIG_MAX_POWER_TABLE_ENABLE
 
     CalcRcpTimeOffset();
 }

src/ncp/ncp_base_radio.cpp

@@ -446,12 +446,12 @@ otError NcpBase::HandlePropertySet_SPINEL_PROP_STREAM_RAW(uint8_t aHeader)
 
     SuccessOrExit(error = DecodeStreamRawTxRequest(*frame));
 
-    // Cache the transaction ID for async response
-    mCurTransmitTID = SPINEL_HEADER_GET_TID(aHeader);
-
     // Pass frame to the radio layer. Note, this fails if we
     // haven't enabled raw stream or are already transmitting.
-    error = otLinkRawTransmit(mInstance, &NcpBase::LinkRawTransmitDone);
+    SuccessOrExit(error = otLinkRawTransmit(mInstance, &NcpBase::LinkRawTransmitDone));
+
+    // Cache the transaction ID for async response
+    mCurTransmitTID = SPINEL_HEADER_GET_TID(aHeader);
 
 exit: