correct incremental restore envvar (#642)

Author: gamefiend

docs/incremental-mysql-backups-and-restores.md

@@ -1,14 +1,14 @@
 # Incremental MySQL Backups and Restores
 
 Customers who have large MySQL databases who wish to save storage space can use the `--incremental` flag with `ghe-backup` and `ghe-restore`.
-Using this flag performs backups for other parts of GHES as normal, but only performs a MySQL backup of the changes to the database from the previous snapshot. 
+Using this flag performs backups for other parts of GHES as normal, but only performs a MySQL backup of the changes to the database from the previous snapshot.
 For larger databases this can conserve a lot of storage space for backups.
 
 ## Configuring number of backups
 
-In your backup.config file you will need to set the variable `GHE_INCREMENTAL_BACKUP_MAX`.
+In your backup.config file you will need to set the variable `GHE_INCREMENTAL_MAX_BACKUPS`.
 This variable determines how many cycles of full and incremental backups will be performed before the next full backup is created.
-For example, if `GHE_INCREMENTAL_BACKUP_MAX` is set to 14, backup-utils will run 1 full backup and then 13 incremental backups before performing another full backup on the next cycle.
+For example, if `GHE_INCREMENTAL_MAX_BACKUPS` is set to 14, backup-utils will run 1 full backup and then 13 incremental backups before performing another full backup on the next cycle.
 
 Incremental backups require the previous snapshot backups before them to work.
 This means they do not follow the pruning strategy based on `GHE_NUM_SNAPSHOTS`.
@@ -19,7 +19,7 @@ To perform incremental backups:
 
 `bin/ghe-backup --incremental`
 
-the program will detect whether it needs to performa full or incremental snapshot based on what is currently in `GHE_DATA_DIR`. 
+the program will detect whether it needs to performa full or incremental snapshot based on what is currently in `GHE_DATA_DIR`.
 
 To see what snapshots are part of your full and incremental backups, you can reference `GHE_DATA_DIR/inc_full_backup` and `GHE_DATA_DIR/inc_snapshot_data`, respectively.
 
@@ -35,4 +35,4 @@ The program will use the MySQL folders from each previous incremental backup and
 
 ### Previous cycles
 
-To ensure there is a rolling window of mySQL backups, incremental MySQL backups from the cycle before the current one are kept.  Those snapshots are pre-pended with `inc_previous`. To perform a restore from there, just use the full directory name for the snapshot id.
+To ensure there is a rolling window of mySQL backups, incremental MySQL backups from the cycle before the current one are kept.  Those snapshots are pre-pended with `inc_previous`. To perform a restore from there, just use the full directory name for the snapshot ID.