build: limit usage of vpath

All paths are now explicitly given, and the object tree mimics
the source tree, so there is no need to apply special vpaths.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/Makefile b/Makefile
index 1d34b95..32550cb 100644
--- a/Makefile
+++ b/Makefile
@@ -33,7 +33,7 @@
 .PHONY: all clean cscope distclean dvi html info install install-doc \
 	pdf recurse-all speed tar tarbin test build-all
 
-$(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
+$(call set-vpath, $(SRC_PATH))
 
 LIBS+=-lz $(LIBS_TOOLS)