lib: lmb: rename lmb_get_unreserved_size to lmb_get_free_size

As a follow-up, change the name of the newly introduced function
'lmb_get_unreserved_size' to 'lmb_get_free_size', which is more
appropriate.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
[trini: Fix test/lib/lmb.c]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/net/tftp.c b/net/tftp.c
index 8fab6d2..eca801a 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -609,7 +609,7 @@
 	lmb_init_and_reserve(&lmb, gd->bd->bi_dram[0].start,
 			     gd->bd->bi_dram[0].size, (void *)gd->fdt_blob);
 
-	max_size = lmb_get_unreserved_size(&lmb, load_addr);
+	max_size = lmb_get_free_size(&lmb, load_addr);
 	if (!max_size)
 		return -1;