Moved LFS_TRACE calls to API wrapper functions

This removes quite a bit of extra code needed to entertwine the
LFS_TRACE calls into the original funcions.

Also changed temporary return type to match API declaration where
necessary.

lfs.h

@@ -16,6 +16,7 @@ extern "C"
 {
 #endif
 
+
 /// Version info ///
 
 // Software library version
@@ -657,6 +658,7 @@ int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
 #endif
 
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif