resample: fix UINT32_MAX fallback

Reported by Mark Harris
diff --git a/libspeexdsp/resample.c b/libspeexdsp/resample.c
index c0a189b..cd2477b 100644
--- a/libspeexdsp/resample.c
+++ b/libspeexdsp/resample.c
@@ -93,7 +93,7 @@
 #endif
 
 #ifndef UINT32_MAX
-#define UINT32_MAX 4294967296U
+#define UINT32_MAX 4294967295U
 #endif
 
 #ifdef USE_SSE