Only create LOCALBIN directory when it does not exist (#1054)

The current code was calling mkdir -p without checking existance first.

This would change the directory's mtime and cause all files underneath to
become "older". Since they declare LOCALBIN directory as a dependency,
they would be downloaded/rebuilt more frequently than needed.

Signed-off-by: Etai Lev Ran <[email protected]>

Author: elevran

Makefile

@@ -337,7 +337,7 @@ release: artifacts release-quickstart verify test # Create a release.
 ## Location to install dependencies to
 LOCALBIN ?= $(shell pwd)/bin
 $(LOCALBIN):
-	mkdir -p $(LOCALBIN)
+	[ -d $@ ] || mkdir -p $@
 
 ## Tool Binaries
 KUBECTL ?= kubectl