This patch is a follow up to http://lists.mysql.com/commits/76678.
When an allocation failure occurs for the buffer in the dynamic
array, an error condition was being set. The dynamic array is
usable even if the memory allocation fails. Since in most cases
the thread can continue to work without any problems the error
condition should not be set here.

This patch adds logic to remove the error condition from being set
when the memory allocation for the buffer in dynamic array fails.