detect: Don't fail while detecting megacli enclosure

The current code was failing as the device enclose doesn't have any
PdType like in :

{'ExitCode': '0x00', 'Adapter0': 'Device at Enclosure - 32, Slot - 14 is
not found'}

src/detect.py

@@ -111,6 +111,11 @@ def detect_megacli(hw_lst):
                     info = megacli.pdinfo(ctrl,
                                           enc['DeviceId'],
                                           disk_num)
+
+                    # If no PdType, it means that's not a disk
+                    if 'PdType' not in info.keys():
+                        continue
+
                     hw_lst.append(('pdisk',
                                    disk,
                                    'ctrl',