scoutfs: trace key struct

The userspace trace event printing code has trouble with arguments that
refer to fields in entries.  Add macros to make entries for all the
fields and use them as the formatted arguments.

We also remove the mapping of zone and type to strings.  It's smaller to
print the values directly and gets rid of some silly code.

Signed-off-by: Zach Brown <zab@versity.com>

kmod/src/Makefile

@@ -6,7 +6,7 @@ CFLAGS_super.o = -DSCOUTFS_GIT_DESCRIBE=\"$(SCOUTFS_GIT_DESCRIBE)\" \
 CFLAGS_scoutfs_trace.o = -I$(src) # define_trace.h double include
  
 scoutfs-y += bio.o btree.o client.o compact.o counters.o data.o dir.o \
-	     export.o extents.o file.o inode.o ioctl.o item.o key.o lock.o \
+	     export.o extents.o file.o inode.o ioctl.o item.o lock.o \
 	     manifest.o msg.o options.o per_task.o seg.o server.o \
 	     scoutfs_trace.o sock.o sort_priv.o super.o sysfs.o trans.o \
 	     triggers.o xattr.o