fix cleanning IMB without GPU

Author: JuliaRS

src_cpp/MPI1/Makefile.MPI1.mk

@@ -86,9 +86,11 @@ override CPPFLAGS += -I${ZE_INCLUDE_DIR} -DZE_INCLUDE_DIR
 endif
 ifndef CUDA_INCLUDE_DIR
 ifndef ZE_INCLUDE_DIR
+ifneq (clean, $(filter clean,$(MAKECMDGOALS)))
 $(error CUDA_INCLUDE_DIR and ZE_INCLUDE_DIR are not set) 
 endif
 endif
+endif
 SUBDIR:=GPU
 else
 SUBDIR:=CPU