assertions.c: decorate assert_that_double error output
assertions.c: decorate assert_that_double error output

The string is supposed to have end of line before printing
expected and actual values, so add it there.

Signed-off-by: Yauheni Kaliuta <e7ceff260c6247953eacadcae73cda3b5436b6ed@gmail.com>

cgreen-devs/cgreen,thoni56/cgreen,matthargett/cgreen,cgreen-devs/cgreen,ykaliuta/cgreen,thoni56/cgreen,matthargett/cgreen,gardenia/cgreen,ykaliuta/cgreen,thoni56/cgreen,thoni56/cgreen,ykaliuta/cgreen,gardenia/cgreen,cgreen-devs/cgreen,gardenia/cgreen,cgreen-devs/cgreen,ykaliuta/cgreen,thoni56/cgreen,matthargett/cgreen,ykaliuta/cgreen,gardenia/cgreen,cgreen-devs/cgreen,matthargett/cgreen,gardenia/cgreen,matthargett/cgreen