Enhance logging around snapshot create/delete

[agrare]

Log the snapshot ref to INFO for both create and delete

https://bugzilla.redhat.com/show_bug.cgi?id=1549299

[agrare]

@miq-bot assign @roliveri

[miq-bot]

Checked commit agrare@5b615bc with ruby 2.3.3, rubocop 0.52.0, haml-lint 0.20.0, and yamllint 1.10.0
1 file checked, 8 offenses detected

lib/VolumeManager/VolMgrPlatformSupportLinux.rb

• ❗ - Line 43, Col 5 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 43, Col 96 - Rails/TimeZone - Do not use Time.now without zone. Use one of Time.zone.now, Time.current, Time.now.in_time_zone, Time.now.utc, Time.now.getlocal, Time.now.iso8601, Time.now.jisx0301, Time.now.rfc3339, Time.now.to_i, Time.now.to_f instead.
• ❗ - Line 49, Col 5 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 55, Col 9 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 57, Col 9 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 60, Col 11 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 62, Col 11 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.
• ❗ - Line 63, Col 11 - Style/MethodCallWithArgsParentheses - Use parentheses for method calls with arguments.

[jerryk55]

Make this at least info to coincide with the call in preMount.

[agrare]

I was thinking the pre/post symmetry was that they both logged to info the result after the operation:
$log.info "VolMgrPlatformSupportLinux.preMount: VM snapshot [#{@snMor}] created in [#{Time.now - st}] seconds"
and
$log.info "#{log_prefix}: VM snapshot [#{@snMor}] removed"
But I can just make this info.

[agrare]

Or we can add a INFO -- Creating snapshot to preMount, thoughts?

[jerryk55]

Oh you're right @agrare I didn't see the second line.

[agrare]

@roliveri just amended the commit to include the BZ link

[simaishi]

Fine backport (to manageiq-gems-pending repo) details:

$ git log -1
commit 32876723bd9de189e87cc7b5927aa38ac55843d7
Author: Richard Oliveri <oliveri.richard.github@gmail.com>
Date:   Tue Feb 27 13:07:00 2018 -0500

    Merge pull request #56 from agrare/additional_create_delete_snapshot_logging
    
    Enhance logging around snapshot create/delete
    (cherry picked from commit 24f925e9a7b8feb6c87fcd8542b7dd2e63ba1bb6)

[simaishi]

@miq-bot add_label fine/backported