dyndbg: add missing MODULE_DESCRIPTION() macro

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in lib/test_dynamic_debug.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240531-md-test_dynamic_debug-v1-1-2194b477f55e@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>