XMPMeta.cpp: fix macro to cast argument to match type

The OutProcHexInt(num) macro fills in its argument via
snprintf's "..." varargs part, and the type at the use
site depends on the passed-in types.  This might cause
wrong types on the stack that cause undefined behavior
in the snprintf() function, and reading past memory,
outputting garbage.

Cast the macro argument to (long) to match the %lX
format string first, to get the expected type width.

Author: mandree

xmpsdk/src/XMPMeta.cpp

@@ -87,7 +87,7 @@ static const char * kTenSpaces = "          ";
 #define OutProcHexInt(num)	{ snprintf ( buffer, sizeof(buffer), "%X", (num) ); /* AUDIT: Using sizeof for snprintf length is safe */	\
 							  status = (*outProc) ( refCon, buffer, strlen(buffer) );  if ( status != 0 ) goto EXIT; }
 #else
-#define OutProcHexInt(num)	{ snprintf ( buffer, sizeof(buffer), "%lX", (num) ); /* AUDIT: Using sizeof for snprintf length is safe */	\
+#define OutProcHexInt(num)	{ snprintf ( buffer, sizeof(buffer), "%lX", (long)(num) ); /* AUDIT: Using sizeof for snprintf length is safe */	\
 							  status = (*outProc) ( refCon, buffer, strlen(buffer) );  if ( status != 0 ) goto EXIT; }
 #endif