dm persistent data: cleanup dm-thin specific references in text

DM's persistent-data library is now used my multiple targets so
exclusive references to "pool" or "thin provisioning" need to be
cleaned up.  Adjust Kconfig's DM_DEBUG_BLOCK_STACK_TRACING text
and remove "pool" from a block manager error message.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index f2ccbc3..7441344 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -250,12 +250,12 @@
          Provides thin provisioning and snapshots that share a data store.
 
 config DM_DEBUG_BLOCK_STACK_TRACING
-	boolean "Keep stack trace of thin provisioning block lock holders"
-	depends on STACKTRACE_SUPPORT && DM_THIN_PROVISIONING
+	boolean "Keep stack trace of persistent data block lock holders"
+	depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA
 	select STACKTRACE
 	---help---
 	  Enable this for messages that may help debug problems with the
-	  block manager locking used by thin provisioning.
+	  block manager locking used by thin provisioning and caching.
 
 	  If unsure, say N.