Fix delimiter matching in rd_pick_partition
Fix delimiter matching in rd_pick_partition

This patch doesn't change the resulting code, but avoids having
duplicate opening parentheses in #if/#else/#endif branches that
confuse text editors.

Change-Id: I0833286173551c16fe9e54e515705307b3468704

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom