engine: Remove redundant method from ISCSIStorageHelper

Change-Id: I5450682f8e611a398405ec0f126e7d4e10cfbd7d
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>
engine: Populate error message placeholder in HotPlugDiskToVmCommand

Trying to deactivate a locked disk will throw the error with the
{diskAliases} placeholder which now is populated with the actual disk
alias.

Change-Id: Iff5224477b8ba547ea7dcde9069ec8874fa8ed24
Bug-Url: https://bugzilla.redhat.com/1031386
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>
engine: Move AddStorageDomainCommand.checkExistingStorageDomain

There is no reason to keep this method in the base class
AddStorageDomainCommand just because it used by one of it's successors.
I am moving it to AddExistingFileStorageDomainCommand.

As a result of this change concreteCheckExistingStorageDomain() method
can be removed from the base class.

Change-Id: I2002f942d32aacf7bbcaa8b6caef3bb744d2dd48
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>
engine: Simplify AddExistingFileStorageDomainCommand

1. Use regular imports instead of inline.
2. Use quick return in case of failure.
3. Use shorter runVdsCommand.

Change-Id: I21960f64d45c01a65978a44d5874b8c94dfb9420
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>
engine: Remove StorageType.ALL value

This value is used only by GetVGListVDSCommand, but the fact we are
talking about VGs implies that this is a block storage - ISCSI or FCP
so in case we can't determine its exact type the UNKNOWN option is
probably more suitable than ALL.

Change-Id: I761d322f88304353bb11fceeed39305dd6698045
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>
engine: Remove concreteStorageType property from StorageType enum.

StorageType enum represents all supported types of storage,
unfortunately it also contains UNKNOWN(0) and ALL(-1) values which are
not a real storage types. In order to establish which type is real this
enum doesn't need additional state 'concreteStorageType', it can just
check the value.

Change-Id: Ibdd785ccb3c0e074f5a14bec1ee60c6d374700a1
Signed-off-by: Sergey Gotliv <sgotliv@redhat.com>