fs: make locks.c explicitly non-modular

fs: make locks.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

config FILE_LOCKING
     bool "Enable POSIX file locking API" if EXPERT

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering gets bumped to one level earlier when we
use the more appropriate fs_initcall here.  However we've made similar
changes before without any fallout and none is expected here either.

Cc: Jeff Layton <[email protected]>
Acked-by: Jeff Layton <[email protected]>
Cc: "J. Bruce Fields" <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: [email protected]
Signed-off-by: Paul Gortmaker <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>