[PATCH] fs/proc: Fix compile warning about variable 'vmcore_mmap_ops'

[Qi Xi <xiqi2@xxxxxxxxxx>]

When build with !CONFIG_MMU, the variable 'vmcore_mmap_ops'
is defined but not used:

>> fs/proc/vmcore.c:458:42: warning: unused variable 'vmcore_mmap_ops'
     458 | static const struct vm_operations_struct vmcore_mmap_ops = {

Fix this by declaring it __maybe_unused.

Fixes: 9cb218131de1 ("vmcore: introduce remap_oldmem_pfn_range()")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/lkml/202410301936.GcE8yUos-lkp@xxxxxxxxx/
Signed-off-by: Qi Xi <xiqi2@xxxxxxxxxx>
---
 fs/proc/vmcore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 1fb213f379a5..9651f105c25b 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -455,7 +455,7 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
 #endif
 }
 
-static const struct vm_operations_struct vmcore_mmap_ops = {
+static const struct vm_operations_struct __maybe_unused vmcore_mmap_ops = {
 	.fault = mmap_vmcore_fault,
 };
 
-- 
2.33.0