dmime: Sign-compare warning fix.

dlls/dmime/dmutils.c

diff --git a/dlls/dmime/dmutils.c b/dlls/dmime/dmutils.c
index 1a822ba..87668cb 100644
--- a/dlls/dmime/dmutils.c
+++ b/dlls/dmime/dmutils.c
@@ -617,7 +617,8 @@
 /* generic flag-dumping function */
 static const char* debugstr_flags (DWORD flags, const flag_info* names, size_t num_names){
 	static char buffer[128] = "", *ptr = &buffer[0];
-	unsigned int i, size = sizeof(buffer);
+	unsigned int i;
+	int size = sizeof(buffer);
 		
 	for (i=0; i < num_names; i++) {
 		if ((flags & names[i].val)) {