powerpc/kernel: Avoid initializing device-tree pointer twice

As commit 50ba08f3 ("of/fdt: Don't clear initial_boot_params
if fdt_check_header() fails") does, the device-tree pointer
"initial_boot_params" is initialized by early_init_dt_verify(),
which is called by early_init_devtree(). So we needn't explicitly
initialize that again in early_init_devtree().
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/prom.c

@@ -652,9 +652,6 @@ void __init early_init_devtree(void *params)
 	if (!early_init_dt_verify(params))
 		panic("BUG: Failed verifying flat device tree, bad version?");
 
-	/* Setup flat device-tree pointer */
-	initial_boot_params = params;
-
 #ifdef CONFIG_PPC_RTAS
 	/* Some machines might need RTAS info for debugging, grab it now. */
 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);