use %u for size_t on microsoft compilers

libobs/util/c99defs.h

@@ -57,10 +57,14 @@ typedef long off_t;
 typedef int64_t off64_t;
 #endif /* __off_t_defined */
 
+#define SIZE_T_FORMAT "%u"
+
 #else
 
 #include <stdint.h>
 #include <stdbool.h>
 #include <sys/types.h>
 
+#define SIZE_T_FORMAT "%zu"
+
 #endif /* _MSC_VER */

obs/obs-app.cpp

@@ -31,7 +31,7 @@ IMPLEMENT_APP(OBSApp);
 
 OBSAppBase::~OBSAppBase()
 {
-	blog(LOG_INFO, "Number of memory leaks: %zu", bnum_allocs());
+	blog(LOG_INFO, "Number of memory leaks: " SIZE_T_FORMAT, bnum_allocs());
 }
 
 static void do_log(enum log_type type, const char *msg, va_list args)