DO NOT MERGE: fix build try #2

On klp-dev, UINT16_MAX isn't available unless __STDINT_LIMITS
is defined, which it's not for this code. This isn't relevant
for later branches due to bionic commit
e2a292d278b94fec3d078b1f1b27c1f89942c276

Don't use UINT16_MAX when we can just hardcode 65535.

Bug: 23905002
Change-Id: Ia1fd0f749cb7a4d19866075abc28ed6960424e54