mm: memfd_luo: add CONFIG_SHMEM dependency

The new memfd code fails to link without SHMEM:

aarch64-linux-ld: mm/memfd_luo.o: in function `memfd_luo_retrieve_folios':
memfd_luo.c:(.text.memfd_luo_retrieve_folios+0xdc): undefined reference to `shmem_add_to_page_cache'
memfd_luo.c:(.text.memfd_luo_retrieve_folios+0x11c): undefined reference to `shmem_inode_acct_blocks'
memfd_luo.c:(.text.memfd_luo_retrieve_folios+0x134): undefined reference to `shmem_recalc_inode'

Add a Kconfig dependency to disallow that configuration.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b3749f1 ("mm: memfd_luo: allow preserving memfd")
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Pratyush Yadav <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Pasha Tatashin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: arndb

kernel/liveupdate/Kconfig

@@ -54,6 +54,7 @@ config KEXEC_HANDOVER_ENABLE_DEFAULT
 config LIVEUPDATE
 	bool "Live Update Orchestrator"
 	depends on KEXEC_HANDOVER
+	depends on SHMEM
 	help
 	  Enable the Live Update Orchestrator. Live Update is a mechanism,
 	  typically based on kexec, that allows the kernel to be updated