ext4: simplify handling of the errors=* mount options

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index df93dc1..d70b981 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -924,6 +924,7 @@
 #define EXT4_MOUNT_ERRORS_CONT		0x00010	/* Continue on errors */
 #define EXT4_MOUNT_ERRORS_RO		0x00020	/* Remount fs ro on errors */
 #define EXT4_MOUNT_ERRORS_PANIC		0x00040	/* Panic on errors */
+#define EXT4_MOUNT_ERRORS_MASK		0x00070
 #define EXT4_MOUNT_MINIX_DF		0x00080	/* Mimics the Minix statfs */
 #define EXT4_MOUNT_NOLOAD		0x00100	/* Don't use existing journal*/
 #define EXT4_MOUNT_DATA_FLAGS		0x00C00	/* Mode for data writes: */