ldattach: add __format__ attribute

Reported-by: Jan Pazdziora <jpazdziora@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

sys-utils/ldattach.c

@@ -130,7 +130,8 @@ static const struct ld_table ld_iflags[] =
 	{ NULL,		0 }
 };
 
-static void dbg(char *fmt, ...)
+static void __attribute__((__format__ (__printf__, 1, 2)))
+	dbg(char *fmt, ...)
 {
 	va_list args;