of: fdt: do not update local variable after use

Fix the below warning:
drivers/of/fdt.c:196:4: warning: Value stored to 'pprev' is never read
[clang-analyzer-deadcode.DeadStores]
             pprev      = &pp->next;
             ^            ~~~~~~~~~
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Link: https://lore.kernel.org/r/20210803101309.904-1-ohoono.kwon@samsung.comSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/fdt.c

@@ -193,7 +193,6 @@ static void populate_properties(const void *blob,
 			pp->length = len;
 			pp->value  = pp + 1;
 			*pprev     = pp;
-			pprev      = &pp->next;
 			memcpy(pp->value, ps, len - 1);
 			((char *)pp->value)[len - 1] = 0;
 			pr_debug("fixed up name for %s -> %s\n",