avutil: Include io.h with a separate condition from windows console functions

Not all versions of windows have the console color functions,
while io.h might be needed for isatty (which can be found in
unistd.h or io.h).
Signed-off-by: Martin Storsjö <martin@martin.st>

libavutil/log.c

@@ -29,6 +29,9 @@
 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#if HAVE_IO_H
+#include <io.h>
+#endif
 #include <stdlib.h>
 #include "avstring.h"
 #include "avutil.h"
@@ -40,7 +43,6 @@ static int flags;
 
 #if defined(_WIN32) && !defined(__MINGW32CE__)
 #include <windows.h>
-#include <io.h>
 static const uint8_t color[] = { 12, 12, 12, 14, 7, 10, 11 };
 static int16_t background, attr_orig;
 static HANDLE con;