ext4: add missing save_error_info() to ext4_error()

commit f3fc0210 upstream.

The ext4_error() function is missing a call to save_error_info().
Since this is the function which marks the file system as containing
an error, this oversight (which was introduced in 2.6.36) is quite
significant, and should be backported to older stable kernels with
high urgency.
Reported-by: Ken Sumrall <ksumrall@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: ksumrall@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/super.c

@@ -497,6 +497,7 @@ void __ext4_error(struct super_block *sb, const char *function,
 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 	       sb->s_id, function, line, current->comm, &vaf);
 	va_end(args);
+	save_error_info(sb, function, line);
 
 	ext4_handle_error(sb);
 }