Use --master-data, not --dump-slave, in bin/storage dump

Summary: These flags do slightly different things, I actually want --master-data here. My test databases are setup half-weird and work with either statement, which is why I missed this.

Test Plan: Ran a dump against master, got the right CHANGE MASTER statement with no warnings.

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D15716

src/docs/user/cluster/cluster_databases.diviner

@@ -302,7 +302,7 @@ this command //from// that host, to avoid sending the whole dump over the
 network).
 
 With the `--for-replica` flag, the `bin/storage dump` command creates dumps
-with `--dump-slave`, which includes a `CHANGE MASTER` statement in the output.
+with `--master-data`, which includes a `CHANGE MASTER` statement in the output.
 This may be helpful when initially setting up new replicas, as it can make it
 easier to change the binlog coordinates to the correct position for the dump.
 

src/infrastructure/storage/management/workflow/PhabricatorStorageManagementDumpWorkflow.php

@@ -13,7 +13,7 @@ final class PhabricatorStorageManagementDumpWorkflow
           array(
             'name' => 'for-replica',
             'help' => pht(
-              'Add __--dump-slave__ to the __mysqldump__ command, '.
+              'Add __--master-data__ to the __mysqldump__ command, '.
               'generating a CHANGE MASTER statement in the output.'),
           ),
         ));
@@ -57,7 +57,7 @@ final class PhabricatorStorageManagementDumpWorkflow
     $argv[] = '--default-character-set=utf8';
 
     if ($args->getArg('for-replica')) {
-      $argv[] = '--dump-slave';
+      $argv[] = '--master-data';
     }
 
     $argv[] = '-u';