bcachefs: Use bch2_print_string_as_lines for long err

printk strings get truncated to 1024 bytes; if we have a long error
message (journal debug info) we need to use a helper.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/journal_io.c

@@ -1967,7 +1967,6 @@ CLOSURE_CALLBACK(bch2_journal_write)
 	struct journal *j = container_of(w, struct journal, buf[w->idx]);
 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
 	struct bch_replicas_padded replicas;
-	struct printbuf journal_debug_buf = PRINTBUF;
 	unsigned nr_rw_members = 0;
 	int ret;
 
@@ -2011,11 +2010,15 @@ CLOSURE_CALLBACK(bch2_journal_write)
 	}
 
 	if (ret) {
-		__bch2_journal_debug_to_text(&journal_debug_buf, j);
+		struct printbuf buf = PRINTBUF;
+		buf.atomic++;
+
+		prt_printf(&buf, bch2_fmt(c, "Unable to allocate journal write: %s"),
+			   bch2_err_str(ret));
+		__bch2_journal_debug_to_text(&buf, j);
 		spin_unlock(&j->lock);
-		bch_err(c, "Unable to allocate journal write:\n%s",
-			journal_debug_buf.buf);
-		printbuf_exit(&journal_debug_buf);
+		bch2_print_string_as_lines(KERN_ERR, buf.buf);
+		printbuf_exit(&buf);
 		goto err;
 	}