ha_partition::init_record_priority_queue()

Cherry-pick rev.6b0ee0c795499cee7f9deb649fb010801e0be4c2 from mysql-5.6.

Bug #18305270  BACKPORT BUG#18694052 FIX
               FOR ASSERTION `!M_ORDERED_REC_BUFFER'
               FAILED TO 5.6

PROBLEM
-------
Missed to remove record priority queue if
init_index failed for a partition which
was causing the crash.

FIX
---
Remove priority queue if init_index fails
for partition.