In the following commit:
commit 
57673c2b0baa900dddae3b9eb3d7748ebf550eb3
Author: Rusty Russell <rusty@rustcorp.com.au>
Date:   Mon Mar 31 14:39:57 2014 +1030
    Use 'E' instead of 'X' for unsigned module taint flag.
One site has been forgotten in trace events module.h.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
        { (1UL << TAINT_OOT_MODULE),            "O" },          \
        { (1UL << TAINT_FORCED_MODULE),         "F" },          \
        { (1UL << TAINT_CRAP),                  "C" },          \
-       { (1UL << TAINT_UNSIGNED_MODULE),       "X" })
+       { (1UL << TAINT_UNSIGNED_MODULE),       "E" })
 
 TRACE_EVENT(module_load,