btm_cb.busy_level can never equal BTM_BL_PAGING_STARTED

busy_level is only ever 10 or the number of links, which cannot exceed 7

BTM_BL_PAGING_STARTED is equal to 0x14

I rest my case.

Bug: 159815595
Tag: #refactor
Test: compile & verify basic functions working
Change-Id: I7a656b5c15d5418eb65351807febe3e020fdf331