vmcore: move get_vmcore_size out of __init

Fix below build warning:

WARNING: vmlinux.o(.text+0x422bb8): Section mismatch in reference from
the function vmcore_add_device_dump() to the function
.init.text:get_vmcore_size.constprop.5()

The function vmcore_add_device_dump() references
the function __init get_vmcore_size.constprop.5().
This is often because vmcore_add_device_dump lacks a __init
annotation or the annotation of get_vmcore_size.constprop.5 is wrong.

Fixes: 7efe48df ("vmcore: append device dumps to vmcore as elf notes")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fs/proc/vmcore.c

@@ -649,8 +649,8 @@ static struct vmcore* __init get_new_element(void)
 	return kzalloc(sizeof(struct vmcore), GFP_KERNEL);
 }
 
-static u64 __init get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
-				  struct list_head *vc_list)
+static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
+			   struct list_head *vc_list)
 {
 	u64 size;
 	struct vmcore *m;