fmbtgti: fix exception on screenshot garbage collection
fmbtgti: fix exception on screenshot garbage collection

mixu-/fMBT,violep01/fMBT,mixu-/fMBT,01org/fMBT,violep01/fMBT,yoonkiss/fMBT,01org/fMBT,mixu-/fMBT,yoonkiss/fMBT,violep01/fMBT,yoonkiss/fMBT,01org/fMBT,mixu-/fMBT,mixu-/fMBT,yoonkiss/fMBT,01org/fMBT,yoonkiss/fMBT,violep01/fMBT,violep01/fMBT,01org/fMBT