64d7b6cf75
When using zdb with non-default SPA config file it is not convenient to add -U <non-default-config-file-path> all the time. This commit introduces support for setting/overriding SPA config location via environment variable 'SPA_CONFIG_PATH'. If -U flag is specified in the command line it will override any other value as usual. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1545