Don't free the stream on error if we've successfully added it
to the hash table, since it will be freed by virChrdevHashEntryFree
callback.
Preserve the error message before calling virStreamFree, since it
resets the error.
Introduced by 4716138, crashing since 6921892.
Reported by Sergey Fionov on libvir-list.
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
This also changes the function signature to take a
virDomainChrSourceDefPtr instead of just a path, since it needs to
differentiate behavior based on source->type.
The functionality provided in virchrdev.c (previously virconsole.c) is
applicable to other types of character devices besides consoles, such
as channels. This patch is just code motion, renaming things such as
"console" or "pty", instead using more general terms such as
"character device" or "device path".
