lmb: Rename free_mem to available_mem

free_mem is a misnomer. We never update it with the free memory for
LMB. Instead, it describes all available memory and is checked against
used_mem to decide whether an area is free or not.

So let's rename this field to better match its usage.

Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Tested-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/include/lmb.h b/include/lmb.h
index 3abe24d..18030c6 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -45,12 +45,12 @@
 
 /**
  * struct lmb - The LMB structure
- * @free_mem: List of free memory regions
+ * @available_mem: List of memory available to LMB
  * @used_mem: List of used/reserved memory regions
  * @test: Is structure being used for LMB tests
  */
 struct lmb {
-	struct alist free_mem;
+	struct alist available_mem;
 	struct alist used_mem;
 	bool test;
 };