mm: replace module_init usages with subsys_initcall in nommu.c

Compiling some arm/m68k configs with "# CONFIG_MMU is not set" reveals
two more instances of module_init being used for code that can't
possibly be modular, as CONFIG_MMU is either on or off.

We replace them with subsys_initcall as per what was done in other
mmu-enabled code.

Note that direct use of __initcall is discouraged, vs.  one of the
priority categorized subgroups.  As __initcall gets mapped onto
device_initcall, our use of subsys_initcall (which makes sense for these
files) will thus change this registration from level 6-device to level
4-subsys (i.e.  slightly earlier).

One might think that core_initcall (l2) or postcore_initcall (l3) would
be more appropriate for anything in mm/ but if we look at the actual init
functions themselves, we see they are just sysctl setup stuff, and
hence the choice of subsys_initcall (l4) seems reasonable.  At the same
time it minimizes the risk of changing the priority too drastically all
at once.  We can adjust further in the future.

Also, a couple instances of missing ";" at EOL are fixed.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>