pds_core: handle unsupported PDS_CORE_CMD_FW_CONTROL result

In the Linux kernel, the following vulnerability has been resolved: pds_core: handle unsupported PDS_CORE_CMD_FW_CONTROL result If the FW doesn't support the PDS_CORE_CMD_FW_CONTROL command the driver might at the least print garbage and at the worst crash when the user runs the "devlink dev info" devlink command. This happens because the stack variable fw_list is not 0 initialized which results in fw_list.num_fw_slots being a garbage value from the stack. Then the driver tries to access fw_list.fw_names[i] with i >= ARRAY_SIZE and runs off the end of the array. Fix this by initializing the fw_list and by not failing completely if the devcmd fails because other useful information is printed via devlink dev info even if the devcmd fails.