Replaced __linux macro with __linux__

src/libslic3r/GCodeSender.cpp

@@ -134,7 +134,7 @@ GCodeSender::set_baud_rate(unsigned int baud_rate)
         speed_t newSpeed = baud_rate;
         ioctl(handle, IOSSIOSPEED, &newSpeed);
         ::tcsetattr(handle, TCSANOW, &ios);
-#elif __linux
+#elif __linux__
         termios2 ios;
         if (ioctl(handle, TCGETS2, &ios))
             printf("Error in TCGETS2: %s\n", strerror(errno));

src/libslic3r/utils.cpp

@@ -39,9 +39,9 @@
 
 #include <tbb/task_scheduler_init.h>
 
-#if defined(__linux) || defined(__GNUC__ )
+#if defined(__linux__) || defined(__GNUC__ )
 #include <strings.h>
-#endif /* __linux */
+#endif /* __linux__ */
 
 #ifdef _MSC_VER 
     #define strcasecmp _stricmp