vp8: Include the thread headers before using the pthread types

This was unnoticed on linux, since stdlib.h apparently includes
files declaring the pthread_mutex_t and pthread_cond_t types.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

libavcodec/vp8.c

@@ -31,12 +31,6 @@
 #include "rectangle.h"
 #include "thread.h"
 
-#if HAVE_PTHREADS
-#include <pthread.h>
-#elif HAVE_W32THREADS
-#include "w32pthreads.h"
-#endif
-
 #if ARCH_ARM
 #   include "arm/vp8.h"
 #endif

libavcodec/vp8.h

@@ -30,6 +30,11 @@
 #include "vp56data.h"
 #include "vp8dsp.h"
 #include "h264pred.h"
+#if HAVE_PTHREADS
+#include <pthread.h>
+#elif HAVE_W32THREADS
+#include "w32pthreads.h"
+#endif
 
 #define VP8_MAX_QUANT 127