The optimization of sysctlbyname() in commit d05b53e0ba had the
side-effect of not going through the fix-up for the user.* variables
in the previously called sysctl() function.
This lead to 0 or an empty strings being returned by sysctlbyname()
for all user.* variables.
An alternate implementation would store the user variables in the
kernel during system start-up. That would allow to remove the fix-up
code in the C library that is currently required to provide the actual
values.
This update restores the previous code path for the user.* variables
and keeps the performance optimization intact for all other variables.
Approved by: mjg
Reviewed by: kaktus
Differential Revision: https://reviews.freebsd.org/D34171
af7d105379