module: fold usermode helper kmod into modules directory

The kernel/kmod.c is already only built if we enabled modules, so
just stuff it under kernel/module/kmod.c and unify the MAINTAINERS
file for it.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

MAINTAINERS

@@ -11522,16 +11522,6 @@ F:	include/linux/kmemleak.h
 F:	mm/kmemleak.c
 F:	samples/kmemleak/kmemleak-test.c
 
-KMOD KERNEL MODULE LOADER - USERMODE HELPER
-M:	Luis Chamberlain <mcgrof@kernel.org>
-L:	linux-kernel@vger.kernel.org
-L:	linux-modules@vger.kernel.org
-S:	Maintained
-F:	include/linux/kmod.h
-F:	kernel/kmod.c
-F:	lib/test_kmod.c
-F:	tools/testing/selftests/kmod/
-
 KMSAN
 M:	Alexander Potapenko <glider@google.com>
 R:	Marco Elver <elver@google.com>
@@ -14083,8 +14073,11 @@ L:	linux-kernel@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git modules-next
 F:	include/linux/module.h
+F:	include/linux/kmod.h
 F:	kernel/module/
 F:	scripts/module*
+F:	lib/test_kmod.c
+F:	tools/testing/selftests/kmod/
 
 MONOLITHIC POWER SYSTEM PMIC DRIVER
 M:	Saravanan Sekar <sravanhome@gmail.com>

kernel/Makefile

@@ -13,7 +13,6 @@ obj-y     = fork.o exec_domain.o panic.o \
 	    async.o range.o smpboot.o ucount.o regset.o
 
 obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o
-obj-$(CONFIG_MODULES) += kmod.o
 obj-$(CONFIG_MULTIUSER) += groups.o
 
 ifdef CONFIG_FUNCTION_TRACER

kernel/module/Makefile

@@ -7,7 +7,9 @@
 # and produce insane amounts of uninteresting coverage.
 KCOV_INSTRUMENT_module.o := n
 
-obj-y += main.o strict_rwx.o
+obj-y += main.o
+obj-y += strict_rwx.o
+obj-y += kmod.o
 obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
 obj-$(CONFIG_MODULE_SIG) += signing.o
 obj-$(CONFIG_LIVEPATCH) += livepatch.o