Free the memory allocated for cmds/reloc_bos array when destoying the associated ringbuffer.
For similar fix for the non-softpin implementation see: d014af98
Closes: #2324 (closed)
Fixes: f3cc0d27 ("freedreno: import libdrm_freedreno + redesign submit")
Signed-off-by: Lasse Lopperi lasse.lopperi@ge.com