Fix syntax: had to use escaped $$ to have an effect after first expansion.

Author: pnkfelix

mk/host.mk

@@ -128,7 +128,7 @@ $$(HLIB$(2)_H_$(4))/$(CFG_RUSTLLVM_$(4)): \
 	$$(Q)cp $$< $$@
 
 $$(HBIN$(2)_H_$(4))/:
-	mkdir -p $@
+	mkdir -p $$@
 
 endef
 

mk/target.mk

@@ -84,7 +84,7 @@ endif
 endif
 
 $$(TLIB$(1)_T_$(2)_H_$(3))/:
-	mkdir -p $@
+	mkdir -p $$@
 
 endef