Make verify_dump off by default

It's a change of behaviour, so it should be off by default.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/HOWTO b/HOWTO
index ef8f959..41edcf1 100644
--- a/HOWTO
+++ b/HOWTO
@@ -981,7 +981,7 @@
 verify_dump=bool	If set, dump the contents of both the original data
 		block and the data block we read off disk to files. This
 		allows later analysis to inspect just what kind of data
-		corruption occurred. On by default.
+		corruption occurred. Off by default.
 
 verify_async=int	Fio will normally verify IO inline from the submitting
 		thread. This option takes an integer describing how many
diff --git a/fio.1 b/fio.1
index 3b11122..aae7657 100644
--- a/fio.1
+++ b/fio.1
@@ -780,7 +780,7 @@
 .BI verify_dump \fR=\fPbool
 If set, dump the contents of both the original data block and the data block we
 read off disk to files. This allows later analysis to inspect just what kind of
-data corruption occurred. On by default.
+data corruption occurred. Off by default.
 .TP
 .BI verify_async \fR=\fPint
 Fio will normally verify IO inline from the submitting thread. This option
diff --git a/options.c b/options.c
index 4207537..bb46dc9 100644
--- a/options.c
+++ b/options.c
@@ -1581,7 +1581,7 @@
 		.name	= "verify_dump",
 		.type	= FIO_OPT_BOOL,
 		.off1	= td_var_offset(verify_dump),
-		.def	= "1",
+		.def	= "0",
 		.help	= "Dump contents of good and bad blocks on failure",
 		.parent = "verify",
 	},