Windows: MSVC2017: adapt hackrfoutput plugin module

plugins/samplesink/hackrfoutput/hackrfoutput.pro

@@ -19,6 +19,8 @@ QMAKE_CXXFLAGS += -std=c++11
 
 CONFIG(MINGW32):LIBHACKRFSRC = "C:\softs\hackrf\host"
 CONFIG(MINGW64):LIBHACKRFSRC = "C:\softs\hackrf\host"
+CONFIG(MSVC):LIBHACKRFSRC = "C:\softs\hackrf\host"
+
 INCLUDEPATH += $$PWD
 INCLUDEPATH += ../../../exports
 INCLUDEPATH += ../../../sdrbase

plugins/samplesink/hackrfoutput/hackrfoutputthread.cpp

@@ -18,7 +18,6 @@
 
 #include <stdio.h>
 #include <errno.h>
-#include <unistd.h>
 
 #include "dsp/samplesourcefifo.h"