[partition] Remove some slowdown methods when debugging is off

- Running lsblk and mount for debugging purposes can be
   skipped when the debugging is going to be suppressed anyway.
   This will speed things up just a little for regular users.

src/modules/partition/jobs/CreatePartitionTableJob.cpp

@@ -85,6 +85,8 @@ CreatePartitionTableJob::exec()
     cDebug() << "Creating new partition table of type" << table->typeName()
              << ", uncommitted yet:";
 
+    if ( Logger::logLevelEnabled( Logger::LOGDEBUG ) )
+    {
         for ( auto it = PartitionIterator::begin( table );
             it != PartitionIterator::end( table ); ++it )
             cDebug() << *it;
@@ -102,6 +104,7 @@ CreatePartitionTableJob::exec()
         mount.start();
         mount.waitForFinished();
         cDebug() << "mount:\n" << mount.readAllStandardOutput();
+    }
 
     CreatePartitionTableOperation op(*m_device, table);
     op.setStatus(Operation::StatusRunning);