cifs: map NT_STATUS_ERROR_WRITE_PROTECTED to -EROFS

Seems like a more sensible mapping than -EIO.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/netmisc.c

@@ -61,6 +61,7 @@ static const struct smb_to_posix_error mapping_table_ERRDOS[] = {
 	{ERRremcd, -EACCES},
 	{ERRdiffdevice, -EXDEV},
 	{ERRnofiles, -ENOENT},
+	{ERRwriteprot, -EROFS},
 	{ERRbadshare, -ETXTBSY},
 	{ERRlock, -EACCES},
 	{ERRunsup, -EINVAL},

fs/cifs/smberr.h

@@ -76,6 +76,7 @@
 #define ERRnofiles		18	/* A File Search command can find no
 					   more files matching the specified
 					   criteria. */
+#define ERRwriteprot		19	/* media is write protected */
 #define ERRgeneral		31
 #define ERRbadshare		32	/* The sharing mode specified for an
 					   Open conflicts with existing FIDs on