fdt: boot_get_fdt: remove redundant zeroing out

Paranoid programming [1] lies at the foundation of proper software
development, but the repetitive zeroing-out of output arguments in the
context of the same function rather clutters the code and inhibits
further refactoring/optimization than is doing any good.

In boot_get_fdt(), we already perform zero/NULL-initialization of
*of_flat_tree and *of_size at the beginning of the function, so doing
the same at function error-out is redundant/superfluous.

Moreover, keeping the code unchanged might encourage the developers to
update *of_flat_tree and *of_size during some interim computations,
which is against the current design of boot_get_fdt(). Currently,
writing useful data into these arguments happens just before
successfully returning from boot_get_fdt() and it should better stay so.

[1] https://blog.regehr.org/archives/1106

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

common/image-fdt.c

@@ -489,8 +489,6 @@ int boot_get_fdt(int flag, int argc, char * const argv[], uint8_t arch,
 no_fdt:
 	ok_no_fdt = 1;
 error:
-	*of_flat_tree = NULL;
-	*of_size = 0;
 	if (!select && ok_no_fdt) {
 		debug("Continuing to boot without FDT\n");
 		return 0;