oem_ibm: Fix pldm crash
oem_ibm: Fix pldm crash

Check for the presence of the directory before iterating
through it. Iterating over a missing directory would crash
pldm.

Signed-off-by: Manojkiran Eda <58c0f11b20f4eee4270d60d1871d69f99fda7b66@gmail.com>
Change-Id: I3296a427cb5e904dbc1fd48a109eedc051cf832d

openbmc/pldm,openbmc/pldm,openbmc/pldm