pstore: Don't allow high traffic options on fragile devices

Some pstore backing devices use on board flash as persistent
storage. These have limited numbers of write cycles so it
is a poor idea to use them from high frequency operations.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/acpi/apei/erst.c

@@ -942,6 +942,7 @@ static int erst_clearer(enum pstore_type_id type, u64 id, int count,
 static struct pstore_info erst_info = {
 	.owner		= THIS_MODULE,
 	.name		= "erst",
+	.flags		= PSTORE_FLAGS_FRAGILE,
 	.open		= erst_open_pstore,
 	.close		= erst_close_pstore,
 	.read		= erst_reader,