Fix format specifier technicalities.

Fix format specifier technicalities.

Various printf() format specifiers in the tree had minor technical issues
which the Mac OS build reported, e.g. here:
https://s3.amazonaws.com/archive.travis-ci.org/jobs/208718342/log.txt

These tend to fall into two categories of harmless warnings:

1. Wrong width for types that are all promoted to 'int'.  For example,
both uint8_t and uint16_t are both promoted to 'int' as part of a call
to printf(), but using PRIu8 for a uint16_t causes a warning.

2. Wrong format specifier for type promoted to 'int' due to arithmetic.
For example, if 'x' is a uint8_t, then x >> 1 has type 'int' due to
C's promotion rules, so the correct format specifier is %d and using
PRIu8 will cause a warning.

This commit fixes the warnings.  I didn't see anything that rose to the
level of a bug.

These warnings only showed up on Mac OS X because of differences in the
format specifiers that Mac OS uses for PRI*.

Reported-by: Shu Shen <shu.shen@gmail.com>
Acked-by: Daniele Di Proietto <diproiettod@vmware.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>