HID: Fix issues reported by Static Analysis Tool

- Update error checking condition in bta_hh_le_co_cache_load API
  to return if either num of report is 0 or if length of report is
  less than size of report cache structure.

- Memset the report descriptor before use to properly initialize variables
  not updated in function.

Test: builds, hid functionality works fine

Bug: 35013844
Change-Id: Ie0347307d7536f18bf8f32a2dfeda593a41933bf