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>

drivers/md/Kconfig

@@ -250,12 +250,12 @@ config DM_THIN_PROVISIONING
          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.
 

drivers/md/persistent-data/dm-block-manager.c

@@ -104,7 +104,7 @@ static int __check_holder(struct block_lock *lock)
 
 	for (i = 0; i < MAX_HOLDERS; i++) {
 		if (lock->holders[i] == current) {
-			DMERR("recursive lock detected in pool metadata");
+			DMERR("recursive lock detected in metadata");
 #ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
 			DMERR("previously held here:");
 			print_stack_trace(lock->traces + i, 4);