butc: avoid freeing uninitialized pointer in writeDbDump()

butc: avoid freeing uninitialized pointer in writeDbDump()

In error conditions, charList could be freed before it is initialized.
Move the initialization up to before the error checks.

Found-by: clang static analyzer
Reviewed-on: http://gerrit.openafs.org/5167
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 43834bff1a2b1af348ff69d538a884bf1070b90c)

Change-Id: I05d1602b3f59b521d7daa3fd23f6609bf14c460e
Reviewed-on: http://gerrit.openafs.org/5224
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>