fix(clang): fix bugprone-narrowing-conversions errors

Remove silent narrowing conversions.
Note in fdt_patch_mem since the conversion of fdt_max_size occurs
on the boundary between hafnium and third_party libaries we use a
cast to make the conversion explicit however the conversion itself
is not removed.

Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
Change-Id: I4ece5be0262ae06e3dc63e5970ec1a014956a43f
diff --git a/src/fdt_patch.c b/src/fdt_patch.c
index 0a4a045..4e7f535 100644
--- a/src/fdt_patch.c
+++ b/src/fdt_patch.c
@@ -52,7 +52,7 @@
 	       struct boot_params_update *p, struct mpool *ppool)
 {
 	void *fdt;
-	size_t buf_size;
+	int buf_size;
 	int off;
 	bool ret = false;
 	bool rsv;
@@ -185,7 +185,7 @@
 	}
 
 	/* Allow some extra room for patches to the FDT. */
-	ret = fdt_open_into(fdt, fdt, fdt_max_size);
+	ret = fdt_open_into(fdt, fdt, (int)fdt_max_size);
 	if (ret != 0) {
 		dlog_error("FDT failed to open_into. Error: %d\n", ret);
 		goto out_unmap_fdt;