jbd2: clarify bad journal block checksum message

There were two error messages emitted by jbd2, one for a bad checksum
for a jbd2 descriptor block, and one for a bad checksum for a jbd2
data block.  Change the data block checksum error so that the two can
be disambiguated.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/jbd2/recovery.c

@@ -600,8 +600,8 @@ static int do_one_pass(journal_t *journal,
 						success = -EFSBADCRC;
 						printk(KERN_ERR "JBD2: Invalid "
 						       "checksum recovering "
-						       "block %llu in log\n",
-						       blocknr);
+						       "data block %llu in "
+						       "log\n", blocknr);
 						block_error = 1;
 						goto skip_write;
 					}