MFC r337458, r337618:
Fix printf(1) ignores width and precision in %b format.

The precision with the conversion specifier b is specified by POSIX: see
point 7 in the reference documentation.

Include fix from jilles@ to avoid breaking the testsuite.

Reference: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/printf.html

PR: 229641
Reported by: Rudolf Cejka
Submitted by: Garrett D'Amore (illumos)