Change type of rd variable
Change type of rd variable

Silences some warnings.

Change-Id: I8e90368a973c1fc4a88a1bb92b779aa68981dbb5

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