ext4: fix endianess problems in ext4 write support

All fields were accessed directly instead of using the proper byte swap
functions. Thus, ext4 write support was only usable on little-endian
architectures. Fix this.

Signed-off-by: Michael Walle <michael@walle.cc>
diff --git a/fs/ext4/ext4_journal.h b/fs/ext4/ext4_journal.h
index d54165c..3d05ad5 100644
--- a/fs/ext4/ext4_journal.h
+++ b/fs/ext4/ext4_journal.h
@@ -115,8 +115,8 @@
 int ext4fs_init_journal(void);
 int ext4fs_log_gdt(char *gd_table);
 int ext4fs_check_journal_state(int recovery_flag);
-int ext4fs_log_journal(char *journal_buffer, long int blknr);
-int ext4fs_put_metadata(char *metadata_buffer, long int blknr);
+int ext4fs_log_journal(char *journal_buffer, uint32_t blknr);
+int ext4fs_put_metadata(char *metadata_buffer, uint32_t blknr);
 void ext4fs_update_journal(void);
 void ext4fs_dump_metadata(void);
 void ext4fs_push_revoke_blk(char *buffer);