Clean up pvq experimental flag in encode_block_pass1()
Clean up pvq experimental flag in encode_block_pass1()

Remove redundant #if statements there.

Change-Id: If6e6000c76899b0c3072e741a22bc3efa7d33739

mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,smarter/aom,luctrudeau/aom,mbebenita/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,smarter/aom,smarter/aom,smarter/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,luctrudeau/aom,luctrudeau/aom,GrokImageCompression/aom,luctrudeau/aom