Get rid of memory leak in remote name request handling

The memory that's osi_malloc here is never freed.
Pointer p is passed either to btm_process_remote_name, or to
btm_sec_rmt_name_request_complete. Inside 2nd method, it's passed to
btm_process_remote_name. In all those places, the content of array is
copied, but the pointer is never released.

Bug: None
Flag: exempt, trivial fix
Test: manual, observe device names are ok during scanning.
Change-Id: I75279b5e0c2901161b51181a3eca120a556e1491