udf: Promote some debugging messages to udf_error

If there is a problem with a scratched disc or loader, it's valuable to know
which error occurred.

Convert some debug messages to udf_error, neaten those messages too.
Add the calculated tag checksum and the read checksum to error message.
Make udf_error a public function and move the logging prototypes together.

Original-patch-by: NamJae Jeon <linkinjeon@gmail.com>
Reviewed-by: NamJae Jeon <linkinjeon@gmail.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 7b27b06..80f47ce 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -92,8 +92,6 @@
 static unsigned int udf_count_free(struct super_block *);
 static int udf_statfs(struct dentry *, struct kstatfs *);
 static int udf_show_options(struct seq_file *, struct vfsmount *);
-static void udf_error(struct super_block *sb, const char *function,
-		      const char *fmt, ...);
 
 struct logicalVolIntegrityDescImpUse *udf_sb_lvidiu(struct udf_sb_info *sbi)
 {
@@ -2096,8 +2094,8 @@
 	return -EINVAL;
 }
 
-static void udf_error(struct super_block *sb, const char *function,
-		      const char *fmt, ...)
+void udf_error(struct super_block *sb, const char *function,
+	       const char *fmt, ...)
 {
 	va_list args;