coccicheck: add M= option to control which dir is processed

Examples:
	make coccicheck M=drivers/net/wireless/
	make coccicheck SUBDIRS=drivers/net/wireless/

Version 2:
	fix patch file names when using M=
	tell coccinelle where the include files are

Version 3:
	Add second include option to support out of tree development
	Fix error message
Signed-off-by: Greg Dietsche <Gregory.Dietsche@cuw.edu>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/coccicheck

@@ -9,14 +9,23 @@ if [ "$C" = "1" -o "$C" = "2" ]; then
 #    FLAGS="-ignore_unknown_options -very_quiet"
 #    OPTIONS=$*
 
-# Workaround for Coccinelle < 0.2.3
+    if [ "$KBUILD_EXTMOD" = "" ] ; then
+        # Workaround for Coccinelle < 0.2.3
         FLAGS="-I $srctree/include -very_quiet"
         shift $(( $# - 1 ))
         OPTIONS=$1
+    else
+	echo M= is not currently supported when C=1 or C=2
+	exit 1
+    fi
 else
     ONLINE=0
     FLAGS="-very_quiet"
+    if [ "$KBUILD_EXTMOD" = "" ] ; then
         OPTIONS="-dir $srctree"
+    else
+        OPTIONS="-dir $KBUILD_EXTMOD -patch $srctree -I $srctree/include -I $KBUILD_EXTMOD/include"
+    fi
 fi
 
 if [ ! -x "$SPATCH" ]; then