Revert "Makefile: Fix install error with make -j option"

This reverts commit d2aae847.

It is completely and utterly broken.  Module install should not build
any files, and adding broken dependencies to "help" it build files is
complete and utter sh*t.

The kernel should not be built by root, and "make install" and "make
module_install" (that for obvious reasons need to be run as root)
absolutely must not build any files.  They should only ever copy the
already-built files over.

So having dependencies for the install targets is wrong, wrong, wrong.

If you try to install a kernel without building it first, you *should*
get errors. The build system shouldn't try to help root build the files.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Makefile

@@ -981,7 +981,7 @@ _modinst_:
 # boot a modules.dep even before / is mounted read-write.  However the
 # boot script depmod is the master version.
 PHONY += _modinst_post
-_modinst_post: include/config/kernel.release _modinst_
+_modinst_post: _modinst_
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modinst
 	$(call cmd,depmod)