[PATCH] kbuild: Get more focus on warnings

[Sam Ravnborg]

The following patch put focus on warnings when compiling.

Kbuild has for a long period supported a quit mode.
The quit mode prints a single line for each file compiled,
thus warnings becomes much more visible.
Example:

  CC      kernel/uid16.o
  CC      kernel/ksyms.o
kernel/ksyms.c:441: warning: `__check_region' is deprecated (declared at include/linux/ioport.h:113)
  CC      kernel/module.o

The old output format can obtained like this:
	$ make V=1

or more permanent with the following assignment in .bashrc:
	KBUILD_VERBOSE=1

If one is concerned about warnings the output from a kernel
build is redirected to a file, or make -s is used.
The advantage of this patch is that the default settings puts focus
on warnings while still providing the user with feedback about the
build process.

Kai Germaschewski has done most of the initial work enabling this
feature, originally inspired from Keith Owens kbuild-2.5 patchset.

	Sam