ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL

ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL

Compilation of ipc/ipc_sysctl.c is controlled by
obj-$(CONFIG_SYSVIPC_SYSCTL)
[see ipc/Makefile]

And CONFIG_SYSVIPC_SYSCTL depends on SYSCTL
[see init/Kconfig]

An SYSCTL is selected by PROC_SYSCTL.
[see fs/proc/Kconfig]

Thus: #ifndef CONFIG_PROC_SYSCTL in ipc/ipc_sysctl.c is impossible, the
fallback can be removed.

Link: https://lkml.kernel.org/r/20210918145337.3369-1-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>