zfs test suite: support device paths with intermediate directories

The code assumed that disks (devices) used for testing are always named
like /dev/foo, but there is no reason for that restriction and we can
easily support paths like /dev/stripe/bar.

tests/sys/cddl/zfs/include/libtest.kshlib

@@ -640,7 +640,7 @@ function wipe_partition_table #<whole_disk_name> [<whole_disk_name> ...]
 	while [[ -n $* ]]; do
 		typeset diskname=$1
 		[ ! -e $diskname ] && log_fail "ERROR: $diskname doesn't exist"
-		if gpart list $(basename $diskname) >/dev/null 2>&1; then
+		if gpart list ${diskname#/dev/} >/dev/null 2>&1; then
 			wait_for 5 1 $GPART destroy -F $diskname
 		else
 			log_note "No GPT partitions detected on $diskname"

tests/sys/cddl/zfs/tests/cache/cache.kshlib

@@ -90,9 +90,7 @@ function verify_cache_device
 
 	# Zpool status returns on the device name sans the /dev, so
 	# if the device contains /dev/ remove it.
-	if [[ $device =~ "^/dev/" ]]; then
-		device=`basename ${device}`
-	fi
+	device=${device#"/dev/"}
 
 	if [[ $WRAPPER == *"smi"* ]]; then
 		$ECHO $device | $EGREP "^c[0-F]+([td][0-F]+)+$" > /dev/null 2>&1

tests/sys/cddl/zfs/tests/cli_root/zpool_add/zpool_add.kshlib

@@ -55,9 +55,7 @@ function iscontained
 	for vdev in $@; do
 
 # remove /dev/dsk in vdev if there is
-		$ECHO $vdev | $GREP "^/dev/" >/dev/null 2>&1
-		(( $? == 0 )) && \
-			vdev=${vdev##*/}
+		vdev=${vdev#/dev/}
 
 		$ZPOOL status "$pool" | $AWK '$1 == vdevname {exit 1}' \
 			vdevname=$vdev >/dev/null 2>&1