x86/setup: Make relocated_ramdisk a local variable of relocate_initrd()

After

0b62f6cb0773 ("x86/microcode/32: Move early loading after paging enable"),

the global variable relocated_ramdisk is no longer used anywhere except
for the relocate_initrd() function. Make it a local variable of that
function.

Signed-off-by: Yuntao Wang <[e-mail]>
Signed-off-by: Borislav Petkov (AMD) <[e-mail]>
Reviewed-by: Baoquan He <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/x86/include/asm/setup.h

···
 #include <asm/bootparam.h>
 #include <asm/x86_init.h>
 
-extern u64 relocated_ramdisk;
-
 /* Interrupt control for vSMPowered x86_64 systems */
 #ifdef CONFIG_X86_64
 void vsmp_init(void);

arch/x86/kernel/setup.c

···
 	_brk_start = 0;
 }
 
-u64 relocated_ramdisk;
-
 #ifdef CONFIG_BLK_DEV_INITRD
 
 static u64 __init get_ramdisk_image(void)
···
 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
 
 	/* We need to move the initrd down into directly mapped mem */
-	relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
+	u64 relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
 						      PFN_PHYS(max_pfn_mapped));
 	if (!relocated_ramdisk)
 		panic("Cannot find place for new RAMDISK of size %lld\n",