kbuild: sparse needs CF not CHECKFLAGS

Documentation/sparse.txt tells to use:

    make C=2 CHECKFLAGS="-D__CHECK_ENDIAN__"

However, this still doesn't enable endian checks. The correct syntax is:

    make C=2 CF="-D__CHECK_ENDIAN__"

This documentation bug was introduced by the following commit:

    commit 1c7bafe7
    Author: Robert P. J. Day <rpjday@mindspring.com>
    Date:   Wed Sep 13 07:57:50 2006 -0400

	kbuild: clarify "make C=" build option

	Clarify the use of "make C=" in the top-level Makefile, and fix a
	typo in the Documentation file.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

This `typo' was not a typo, as `CF' had been introduced much earlier, by:

    commit 7b49bb9a
    Author: viro@ZenIV.linux.org.uk <viro@ZenIV.linux.org.uk>
    Date:   Fri Sep 9 21:14:35 2005 +0100

	[PATCH] kbuild: CF=<arguments> passes arguments to sparse

	Allows to add to sparse arguments without mutilating makefiles - just
	pass CF=<arguments> and they will be added to CHECKFLAGS.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Documentation/sparse.txt

@@ -73,10 +73,10 @@ recompiled, or use "make C=2" to run sparse on the files whether they need to
 be recompiled or not.  The latter is a fast way to check the whole tree if you
 have already built it.
 
-The optional make variable CHECKFLAGS can be used to pass arguments to sparse.
-The build system passes -Wbitwise to sparse automatically.  To perform
-endianness checks, you may define __CHECK_ENDIAN__:
+The optional make variable CF can be used to pass arguments to sparse.  The
+build system passes -Wbitwise to sparse automatically.  To perform endianness
+checks, you may define __CHECK_ENDIAN__:
 
-        make C=2 CHECKFLAGS="-D__CHECK_ENDIAN__"
+        make C=2 CF="-D__CHECK_ENDIAN__"
 
 These checks are disabled by default as they generate a host of warnings.