Make 'dirty'-tag optional when parsing the version

Remember kids, don't do regexes.

linux/Makefile

@@ -99,7 +99,7 @@ USE_VERSION := false
 ifeq ($(shell git describe > /dev/null 2>&1 ; echo $$?), 0)
 	USE_VERSION := true
 	VERSION := $(shell git describe --tags --long --dirty --always | \
-		sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)-\?.*-\(g[0-9a-f]*\)-\(.*\)/\1 \2 \3 \4 \5/g')
+		sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)-\?.*-\(g[0-9a-f]*\)-\?\(.*\)/\1 \2 \3 \4 \5/g')
 	VERSION_MAJOR := $(word 1, $(VERSION))
 	VERSION_MINOR := $(word 2, $(VERSION))
 	VERSION_PATCH := $(word 3, $(VERSION))