Fix read_bool().  Oops.
Fix read_bool().  Oops.

HIPERFIT/futhark,diku-dk/futhark,ihc/futhark,diku-dk/futhark,diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,diku-dk/futhark,HIPERFIT/futhark,ihc/futhark,ihc/futhark