Fix the printing format of some test results in test-bfp-conversions
Fix the printing format of some test results in test-bfp-conversions

fprintf() requires that a printing format matches its respective
argument.
In test-bfp-converstions, both dddf_tests and tdtf_tests are calling
fprintf() with decimal printing formats while the arguments was binary
formats, which is considered an undefined behavior.

Signed-off-by: Tulio Magno Quites Machado Filho <0e1b3d0765ee75ed64fa2e34822e4949a70a1429@linux.ibm.com>

gftg85/libdfp,gftg85/libdfp,gftg85/libdfp,gftg85/libdfp