ocfs2: reduce object size of mlog uses

Using a function for __mlog_printk instead of a macro reduces the object
size of built-in.o by about 190KB, or ~18% overall (x86-64 defconfig
with all ocfs2 options)

  $ size fs/ocfs2/built-in.o*
     text    data     bss     dec     hex filename
   870954  118471  134408 1123833  1125f9 fs/ocfs2/built-in.o,new
  1064081  118071  134408 1316560  1416d0 fs/ocfs2/built-in.o.old

Miscellanea:

 - Move the used-once __mlog_cpu_guess statement expression macro to the
   masklog.c file above the use in __mlog_printk function

 - Simplify the mlog macro moving the and/or logic and level code into
   __mlog_printk

[akpm@linux-foundation.org: export __mlog_printk() to other ocfs2 modules]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>