image-fit: don't set compression if it can't be read

fit_image_get_comp() should not set value -1 in case it can't read
the compression node. Instead, leave the value untouched in that case
as it can be absent and a default value previously defined by the
caller of fit_image_get_comp() should be used.

As a result the warning message
WARNING: 'compression' nodes for ramdisks are deprecated, please fix your .its file!
no longer shows if the compression node is actually absent.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/image-fit.c b/boot/image-fit.c
index df3e5df..21dbd05 100644
--- a/boot/image-fit.c
+++ b/boot/image-fit.c
@@ -477,7 +477,7 @@
 void fit_image_print(const void *fit, int image_noffset, const char *p)
 {
 	char *desc;
-	uint8_t type, arch, os, comp;
+	uint8_t type, arch, os, comp = IH_COMP_NONE;
 	size_t size;
 	ulong load, entry;
 	const void *data;
@@ -794,7 +794,6 @@
 	data = fdt_getprop(fit, noffset, FIT_COMP_PROP, &len);
 	if (data == NULL) {
 		fit_get_debug(fit, noffset, FIT_COMP_PROP, len);
-		*comp = -1;
 		return -1;
 	}