A couple recoverymap fixes.

Fix decoding of P010 narrow range code points. Also fix scaling for
input to OETF during application of the map.

NOTE: tests pass, although there is still an expected failure for
encoding against just P010 input (API-0), sine toneMap() isn't
implemented yet.

Bug: 252835416, 261479255
Test: libjpegrecoverymap_test passes
Change-Id: Ibfd036c6c0cd55de7c5886e32fff69f461cf45d9