HBASE-21812 replaced a for-loop with an each block.
Each block introduces a new scope, so a local variable defined inside it
cannot be accessed afterwards.
NameError: undefined local variable or method `admin' for main:Object
getServerNames at /opt/khp/hbase/bin/draining_servers.rb:81
addServers at /opt/khp/hbase/bin/draining_servers.rb:88
<main> at /opt/khp/hbase/bin/draining_servers.rb:146
This commit defines the admin local variable in the current scope beforehand,
so that we can still access it after the block.
Signed-off-by: Duo Zhang <zhangduo@apache.org>
(cherry picked from commit 2b573ae377be926922f48238c4da45a2289f318f)
d310bf9623