Fix compiler warnings for hp3900 backend

The debian-10-mini build issues the following warnings:

  CC       libhp3900_la-hp3900.lo
In file included from hp3900_sane.c:55,
                 from hp3900.c:60:
hp3900_rts8822.c: In function 'Lamp_Status_Get':
hp3900_rts8822.c:4119:30: warning: bitwise comparison always evaluates to false [-Wtautological-compare]
           && ((data1 & 0x10) == 1)) ? 1 : 0;
                              ^~

This should be fixed.