dec_neon,NeedsHev: micro optimization
dec_neon,NeedsHev: micro optimization

trade 2 compares + 1 logical or for max + compare

Change-Id: I785ad8efdc64db2d0609456d6e7af795ab2117d8

webmproject/libwebp,PKRoma/libwebp,webmproject/libwebp,webmproject/libwebp,webmproject/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp,PKRoma/libwebp,PKRoma/libwebp,PKRoma/libwebp