alloc_tag: move memory_allocation_profiling_sysctls into .rodata

alloc_tag: move memory_allocation_profiling_sysctls into .rodata

Remove the change in file mode permissions done before initializing the
sysctl.  It is not necessary as the writing of the kernel variable will be
blocked by the proc_mem_profiling_handler when writing is disallowed (also
controlled by mem_profiling_support).

Link: https://lkml.kernel.org/r/20251215-jag-alloc_tag_const-v1-1-35ea56a1ce13@kernel.org
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>