Implement PCSC_READER_ANY for pcsc_wait_for_card()

59a21f3 documented the use of
PCSC_READER_ANY but never implemented it.

src/pcsc.c

@@ -610,14 +610,18 @@ int pcsc_wait_for_card(pcsc_ctx_t ctx, unsigned long timeout_ms, size_t* idx)
 	struct pcsc_t* pcsc;
 	LONG result;
 
-	if (!ctx) {
+	if (!ctx || !idx) {
 		return -1;
 	}
 	pcsc = ctx;
 
 	// Prepare reader states for card detection
 	for (size_t i = 0; i < pcsc->reader_count; ++i) {
-		pcsc->reader_states[i].dwCurrentState = SCARD_STATE_EMPTY;
+		if (*idx == PCSC_READER_ANY || *idx == i) {
+			pcsc->reader_states[i].dwCurrentState = SCARD_STATE_EMPTY;
+		} else {
+			pcsc->reader_states[i].dwCurrentState = SCARD_STATE_IGNORE;
+		}
 	}
 
 	// Wait for empty state to change

tools/emv-tool.c

@@ -718,6 +718,7 @@ int main(int argc, char** argv)
 
 	// Wait for card presentation
 	printf("\nPresent card\n");
+	reader_idx = PCSC_READER_ANY;
 	r = pcsc_wait_for_card(pcsc, 5000, &reader_idx);
 	if (r < 0) {
 		printf("PC/SC error\n");