efivars: If pstore_register fails, free unneeded pstore buffer

This is patch 3/3 of a patch set that cleans up pstore_register failure paths.

If efivars fails to register with pstore, there is no point to keeping
the 4 KB buffer around. It's only used by the pstore read/write routines.
Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Reported-by: Naotaka Hamaguchi <n.hamaguchi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

drivers/firmware/efi/efi-pstore.c

@@ -235,7 +235,11 @@ static __init int efivars_pstore_init(void)
 	efi_pstore_info.bufsize = 1024;
 	spin_lock_init(&efi_pstore_info.buf_lock);
 
-	pstore_register(&efi_pstore_info);
+	if (pstore_register(&efi_pstore_info)) {
+		kfree(efi_pstore_info.buf);
+		efi_pstore_info.buf = NULL;
+		efi_pstore_info.bufsize = 0;
+	}
 
 	return 0;
 }