OpenZFS 7104 - increase indirect block size

Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>

OpenZFS-issue: https://www.illumos.org/issues/7104
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/4b5c8e9
Closes #5679

tests/zfs-tests/include/libtest.shlib

@@ -1542,7 +1542,7 @@ function zfs_zones_setup #zone_name zone_root zone_ip
 	#
 	if verify_slog_support ; then
 		typeset sdevs="/var/tmp/sdev1 /var/tmp/sdev2"
-		log_must $MKFILE 100M $sdevs
+		log_must $MKFILE $MINVDEVSIZE $sdevs
 		log_must $ZPOOL add $pool_name log mirror $sdevs
 	fi
 
@@ -2512,7 +2512,7 @@ function verify_slog_support
 	typeset sdev=$dir/b
 
 	$MKDIR -p $dir
-	$MKFILE 64M $vdev $sdev
+	$MKFILE $MINVDEVSIZE $vdev $sdev
 
 	typeset -i ret=0
 	if ! $ZPOOL create -n $pool $vdev log $sdev > /dev/null 2>&1; then