Fix MSVC compilation errors

src/main.c

@@ -1269,11 +1269,11 @@ int main(int argc, char * argv [])
         break;
 
       case CONNTYPE_SPI:
-        port = mmt_strdup(
 #ifdef HAVE_LINUXSPI
-         *default_spi? default_spi:
+        port = mmt_strdup(*default_spi? default_spi: "unknown");
+#else
+        port = mmt_strdup("unknown");
 #endif
-           "unknown");
         break;
 
       case CONNTYPE_LINUXGPIO:

src/whereami.c

@@ -14,6 +14,9 @@ extern "C" {
 
 #if !defined(WAI_MALLOC) || !defined(WAI_FREE) || !defined(WAI_REALLOC)
 #include <stdlib.h>
+#ifndef PATH_MAX
+#define PATH_MAX _MAX_PATH
+#endif
 #include "avrdude.h"
 #include "libavrdude.h"
 #endif