Use RFGetPowerState & RFSetPowerState

This will help fix potential race conditions.

I was not able to generate a problem using ThreadSanitizer but that is
not a proof that the code is correct
https://clang.llvm.org/docs/ThreadSanitizer.html

Thanks to andrei-datcu for the patch
"No data races in EHStatusHandlerThread LudovicRousseau#112"
LudovicRousseau#112

src/eventhandler.c

@@ -285,7 +285,7 @@ static void * EHStatusHandlerThread(READER_CONTEXT * rContext)
  if (rv == IFD_SUCCESS)
  {
  readerState = SCARD_PRESENT | SCARD_POWERED | SCARD_NEGOTIABLE;
- rContext->powerState = POWER_STATE_POWERED;
+ RFSetPowerState(rContext, POWER_STATE_POWERED);
  Log1(PCSC_LOG_DEBUG, "powerState: POWER_STATE_POWERED");
 
  if (rContext->readerState->cardAtrLength > 0)
@@ -300,7 +300,7 @@ static void * EHStatusHandlerThread(READER_CONTEXT * rContext)
  else
  {
  readerState = SCARD_PRESENT | SCARD_SWALLOWED;
- rContext->powerState = POWER_STATE_UNPOWERED;
+ RFSetPowerState(rContext, POWER_STATE_UNPOWERED);
  Log1(PCSC_LOG_DEBUG, "powerState: POWER_STATE_UNPOWERED");
  Log3(PCSC_LOG_ERROR, "Error powering up card: %ld 0x%04lX", rv, rv);
  }
@@ -383,7 +383,7 @@ static void * EHStatusHandlerThread(READER_CONTEXT * rContext)
  rContext->readerState->cardAtrLength = 0;
  rContext->readerState->cardProtocol = SCARD_PROTOCOL_UNDEFINED;
  rContext->readerState->readerState = SCARD_PRESENT;
- rContext->powerState = POWER_STATE_UNPOWERED;
+ RFSetPowerState(rContext, POWER_STATE_UNPOWERED);
  Log1(PCSC_LOG_DEBUG, "powerState: POWER_STATE_UNPOWERED");
  rv = IFD_SUCCESS;
  Log1(PCSC_LOG_INFO, "Skip card power on");
@@ -402,13 +402,13 @@ static void * EHStatusHandlerThread(READER_CONTEXT * rContext)
  if (rv == IFD_SUCCESS)
  {
  rContext->readerState->readerState = SCARD_PRESENT | SCARD_POWERED | SCARD_NEGOTIABLE;
- rContext->powerState = POWER_STATE_POWERED;
+ RFSetPowerState(rContext, POWER_STATE_POWERED);
  Log1(PCSC_LOG_DEBUG, "powerState: POWER_STATE_POWERED");
  }
  else
  {
  rContext->readerState->readerState = SCARD_PRESENT | SCARD_SWALLOWED;
- rContext->powerState = POWER_STATE_UNPOWERED;
+ RFSetPowerState(rContext, POWER_STATE_UNPOWERED);
  Log1(PCSC_LOG_DEBUG, "powerState: POWER_STATE_UNPOWERED");
  rContext->readerState->cardAtrLength = 0;
  }
@@ -456,7 +456,7 @@ static void * EHStatusHandlerThread(READER_CONTEXT * rContext)
  int timeout;
 
 #ifndef DISABLE_ON_DEMAND_POWER_ON
- if (POWER_STATE_POWERED == rContext->powerState)
+ if (POWER_STATE_POWERED == RFGetPowerState(rContext))
  /* The card is powered but not yet used */
  timeout = PCSCLITE_POWER_OFF_GRACE_PERIOD;
  else