backtracetest: add MODULE_DESCRIPTION()

Fix the 'make W=1' warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/backtracetest.o

Link: https://lkml.kernel.org/r/20240518-md-backtracetest-v1-1-fab9f942c139@quicinc.comSigned-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/backtracetest.c

@@ -74,5 +74,6 @@ static void exitf(void)
 
 module_init(backtrace_regression_test);
 module_exit(exitf);
+MODULE_DESCRIPTION("Simple stack backtrace regression test module");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");