fix shellcheck errors. and update git completion

Author: paulirish

.functions

@@ -20,7 +20,7 @@ cdf() {  # short for cdfinder
 # Use `which` along with symlink resolving
 whichlink() {
 	# This dopeass conditional stolen from sheerun's dotfiles
-	$(type -p greadlink readlink | head -1) -f $(which $@)
+	$(type -p greadlink readlink | head -1) -f $(which "$@")
 }