strerrordesc_np() isn't very useful (being just another name for
strerror()), but strerrorname_np() lets you get "ENOSYS" for ENOSYS,
which will make some of our test assertion messages clearer when we
switch over from strerror().
This also adds `%#m` formatting to all the relevant functions.
Test: treehugger
Change-Id: Icfe07a39a307d591c3f4f2a09d008dc021643062
There's little value to having strings for these, but we may as well
for consistency. There's no ELASTERRNO constant we can use to check
whether we've fallen behind again, but these were added in 2009 and
2011 respectively, so we're not likely to have to deal with any more
new errno values any time soon...
Bug: http://b/117755069
Test: ran tests
Change-Id: I5b7155c22cad92c2fe03a0b4c7cae415c37fa186
