Added special strdup to liboptions, to prevent memory leaks for option strings

If you are doing memory leak debugging you don't want to see any leaks when
stopping the program.

src/libsdr/soapy.c

@@ -27,6 +27,7 @@
 #include <SoapySDR/Formats.h>
 #include "soapy.h"
 #include "../libdebug/debug.h"
+#include "../liboptions/options.h"
 
 extern int sdr_rx_overflow;
 
@@ -40,7 +41,7 @@ static uint64_t			tx_count = 0;
 
 static int parse_args(SoapySDRKwargs *args, const char *_args_string)
 {
-	char *args_string = strdup(_args_string), *key, *val;
+	char *args_string = options_strdup(_args_string), *key, *val;
 
 	memset(args, 0, sizeof(*args));
 	while (args_string && *args_string) {