We don't care whether the trim was succesful or not anywhere
except the tests.
Switch it to void and set the buffer error on wrong usage.
---
Patch that tried to shut Coverity up by checking the return values anyway:
https://www.redhat.com/archives/libvir-list/2013-June/msg00650.html
src/util/virbuffer.c | 19 ++++++++++---------
src/util/virbuffer.h | 2 +-
tests/virbuftest.c | 43 ++++++++++++++++---------------------------
tools/virsh.c | 9 +++------
4 files changed, 30 insertions(+), 43 deletions(-)