Don't use GNU make new shell assignment operator

Shell assignment operator "!=" is a new feature in GNU make 4.0
and breaks the chart build on previous versions of make which is
still present in many still supported Linux distros.

Change-Id: I74c3c5e910ff7b1344c3da95fa76d11ec31b37c6
Issue-ID: OOM-2562
Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>
diff --git a/kubernetes/common/Makefile b/kubernetes/common/Makefile
index eb782b4..0e923b7 100644
--- a/kubernetes/common/Makefile
+++ b/kubernetes/common/Makefile
@@ -22,7 +22,7 @@
 EXCLUDES :=
 HELM_CHARTS := $(filter-out $(EXCLUDES), $(sort $(patsubst %/.,%,$(wildcard */.))))
 
-HELM_VER != helm version --template "{{.Version}}"
+HELM_VER := $(shell helm version --template "{{.Version}}")
 
 .PHONY: $(EXCLUDES) $(HELM_CHARTS)