BUG: Fix the return type of random_float_fill
BUG: Fix the return type of random_float_fill

The `random_float_fill` function type is declared with return type `double` but
I think this is a typo. The actual implementation of `random_float_fill` is
`random_standard_uniform_fill_f` which has return type `void`:

void random_standard_uniform_fill_f(bitgen_t *bitgen_state, npy_intp cnt, float *out)

Also, `random_double_fill` is declared with return type `void`. This fixes the
return type of `random_float_fill` to match.

pdebuyl/numpy,mhvk/numpy,mattip/numpy,endolith/numpy,charris/numpy,mhvk/numpy,endolith/numpy,jakirkham/numpy,seberg/numpy,charris/numpy,numpy/numpy,endolith/numpy,anntzer/numpy,mhvk/numpy,mattip/numpy,rgommers/numpy,mhvk/numpy,mhvk/numpy,seberg/numpy,endolith/numpy,jakirkham/numpy,charris/numpy,charris/numpy,jakirkham/numpy,jakirkham/numpy,jakirkham/numpy,anntzer/numpy,numpy/numpy,rgommers/numpy,seberg/numpy,numpy/numpy,rgommers/numpy,pdebuyl/numpy,anntzer/numpy,rgommers/numpy,mattip/numpy,pdebuyl/numpy,numpy/numpy,seberg/numpy,mattip/numpy,pdebuyl/numpy,anntzer/numpy