kbuild: Two simple kbuild patches

foo1.patch:   spelling correction in Makefile
foo2.patch:   replace SUBDIRS with M in Documentation/kbuild/modules.txt

From: Kornilios Kourtis <kkourt@cslab.ece.ntua.gr>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Documentation/kbuild/modules.txt

@@ -23,7 +23,7 @@ with changes in the build system the most portable way to compile a
 module outside the kernel is to use the kernel build system,
 kbuild. Use the following command-line:
 
-make -C path/to/kernel/src SUBDIRS=$PWD modules
+make -C path/to/kernel/src M=$PWD modules
 
 This requires that a makefile exits made in accordance to
 Documentation/kbuild/makefiles.txt. Read that file for more details on
@@ -65,4 +65,4 @@ yourmodule-objs := file1.o file2.o file3.o
 # Invokes the kernel build system to come back to the current
 # directory and build yourmodule.ko.
 default:
-	make -C ${KERNEL_SOURCE} SUBDIRS=`pwd` modules
+	make -C ${KERNEL_SOURCE} M=`pwd` modules

Makefile

@@ -53,7 +53,7 @@ ifndef KBUILD_CHECKSRC
   KBUILD_CHECKSRC = 0
 endif
 
-# Use make M=dir to specify direcotry of external module to build
+# Use make M=dir to specify directory of external module to build
 # Old syntax make ... SUBDIRS=$PWD is still supported
 # Setting the environment variable KBUILD_EXTMOD take precedence
 ifdef SUBDIRS