Fix typo in Makefile

Author: Qubitol

madgraph/iolibs/template_files/madmatrix/madmatrix.mk

@@ -188,7 +188,7 @@ export CXXFLAGS
 override CUDA_HOME = $(patsubst %%/bin/nvcc,%%,$(shell which nvcc 2>/dev/null))
 
 # Set HIP_HOME from the path to hipcc, if it exists
-override HIP_HOME = $(shell hipconfig --rocmpath)
+override HIP_HOME = $(shell hipconfig --rocmpath 2>/dev/null)
 
 # Configure CUDA_INC (for CURAND and NVTX) and NVTX if a CUDA installation exists (see #965)
 ifeq ($(CUDA_HOME),)
@@ -726,7 +726,7 @@ all.$(TAG): $(BUILDDIR)/.build.$(TAG) $(LIBDIR)/lib$(MADMATRIX_LIB).so
 override oldtagsb=`if [ -d $(BUILDDIR) ]; then find $(BUILDDIR) -maxdepth 1 -name '.build.*' ! -name '.build.$(TAG)' -exec echo $(shell pwd)/{} \; ; fi`
 $(BUILDDIR)/.build.$(TAG):
 	@if [ ! -d $(BUILDDIR) ]; then echo "mkdir -p $(BUILDDIR)"; mkdir -p $(BUILDDIR); fi
-	@if [ "$(oldtagsb)" != "" ]; then echo "Cannot build for tag=$(TAG) as old builds exist for other tags:"; echo "  $(oldtagsb)"; echo "Please run 'make clean' first\nIf 'make clean' is not enough: run 'make clean USEBUILDDIR=1 BACKEND=$(BACKEND) FPTYPE=$(FPTYPE)' or 'make cleanall'"; exit 1; fi
+	@if [ "$(oldtagsb)" != "" ]; then echo "Cannot build for tag=$(TAG) as old builds exist for other tags:"; echo "  $(oldtagsb)"; echo "Please run 'make clean' first"; echo "If 'make clean' is not enough: run 'make clean USEBUILDDIR=1 BACKEND=$(BACKEND) FPTYPE=$(FPTYPE)' or 'make cleanall'"; exit 1; fi
 	@touch $(BUILDDIR)/.build.$(TAG)
 
 # Apply special build flags only to CrossSectionKernels.o (no fast math, see #117 and #516)