Postgres upgrade fails when installed on different directory

Description

Postgres upgrade fails when Postgres has been relocated to a different directory.

This particular case had another issue at #1929 (closed) in case its directly related.

Error output

root@aml00238 [/etc/gitlab] # gitlab-ctl pg-upgrade 
Checking for an omnibus managed postgresql: OK 
Checking version of running PostgreSQL: OK 
Checking for a newer version of PostgreSQL to install: OK 
Upgrading PostgreSQL to 9.6.1 
Checking if existing PostgreSQL instances needs to be upgraded: OK 
Checking if the PostgreSQL directory has been symlinked elsewhere: OK 
Checking if PostgreSQL bin files are symlinked to the expected location: OK 
Toggling deploy page:cp /opt/gitlab/embedded/service/gitlab-rails/public/deploy.html /opt/gitlab/embedded/service/gitlab-rails/public/index.html 
Toggling deploy page: OK 
Toggling servicesok down: logrotate: 1s, normally up 
ok: down: sidekiq: 1s, normally up 
Toggling services: OK 
Waiting 30 seconds to ensure tasks complete before PostgreSQL upgrade 
Please hit Ctrl-C now if you want to cancel the upgrade 
Stopping the databaseok down: postgresql: 0s, normally up 
Stopping the database: OK 
Update the symlinks: OK 
Creating temporary data directory: OK 
Initializing the new database: OK 
Upgrading the data:Could not run: /opt/gitlab/embedded/bin/pg_upgrade -b /opt/gitlab/embedded/postgresql/9.2.18/bin -d /var/opt/gitlab/postgresql/data -D /var/opt/gitlab/postgresql/data.9.6.1 -B /opt/gitlab/embedded/bin 
STDOUT: 
check for "/var/opt/gitlab/postgresql/data" failed: No such file or directory

Failure, exiting 
STDERR: 
== Fatal error == 
Please check the output and try again 
== Reverting == 
ok: down: postgresql: 3s, normally up 
ok: run: postgresql: (pid 12184) 1s 
== Reverted == 
== Reverted to 9.2.18. Please check output for what went wrong == 
Toggling deploy page:rm -f /opt/gitlab/embedded/service/gitlab-rails/public/index.html 
Toggling deploy page: OK 
Toggling servicesok run: logrotate: (pid 12196) 0s 
ok: run: sidekiq: (pid 12202) 0s 
Toggling services: OK

/cc @ibaum