xtensa: One function call less in bootmem_init()

Avoid an extra function call by using a ternary operator instead of
a conditional statement for a setting selection.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Message-Id: <495c9f2e-7880-ee9a-5c61-eee598bb24c2@web.de>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/mm/init.c

@@ -45,10 +45,7 @@ void __init bootmem_init(void)
 	 * If PHYS_OFFSET is zero reserve page at address 0:
 	 * successfull allocations should never return NULL.
 	 */
-	if (PHYS_OFFSET)
-		memblock_reserve(0, PHYS_OFFSET);
-	else
-		memblock_reserve(0, 1);
+	memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1);
 
 	early_init_fdt_scan_reserved_mem();