jbd: Revise KERN_EMERG error messages

Some of KERN_EMERG printk messages do not really deserve this log level
and the one in log_wait_commit() is even rather useless (the journal has
been previously aborted and *that* is where we should have been
complaining). So make some messages just KERN_ERR and remove the useless
message.

Signed-off-by: Jan Kara <[e-mail]>

fs/jbd/journal.c

···
 #ifdef CONFIG_JBD_DEBUG
 	spin_lock(&journal->j_state_lock);
 	if (!tid_geq(journal->j_commit_request, tid)) {
-		printk(KERN_EMERG
+		printk(KERN_ERR
 		       "%s: error: j_commit_request=%d, tid=%d\n",
 		       __func__, journal->j_commit_request, tid);
 	}
···
 out_unlock:
 	spin_unlock(&journal->j_state_lock);
 
-	if (unlikely(is_journal_aborted(journal))) {
-		printk(KERN_EMERG "journal commit I/O error\n");
+	if (unlikely(is_journal_aborted(journal)))
 		err = -EIO;
-	}
 	return err;
 }
 
···
 #ifdef CONFIG_JBD_DEBUG
 	int n = atomic_read(&nr_journal_heads);
 	if (n)
-		printk(KERN_EMERG "JBD: leaked %d journal_heads!\n", n);
+		printk(KERN_ERR "JBD: leaked %d journal_heads!\n", n);
 #endif
 	jbd_remove_debugfs_entry();
 	journal_destroy_caches();

fs/jbd/transaction.c

···
 					jbd_alloc(jh2bh(jh)->b_size,
 							 GFP_NOFS);
 				if (!frozen_buffer) {
-					printk(KERN_EMERG
+					printk(KERN_ERR
 					       "%s: OOM for frozen_buffer\n",
 					       __func__);
 					JBUFFER_TRACE(jh, "oom!");
···
 	if (!jh->b_committed_data) {
 		committed_data = jbd_alloc(jh2bh(jh)->b_size, GFP_NOFS);
 		if (!committed_data) {
-			printk(KERN_EMERG "%s: No memory for committed data\n",
+			printk(KERN_ERR "%s: No memory for committed data\n",
 				__func__);
 			err = -ENOMEM;
 			goto out;