Fix `go vet` issues

Test: go vet ./...
Change-Id: Ifb936ccc5e2b5a2c3fcbbbcb54f680e2973ea1b3
diff --git a/android/makevars.go b/android/makevars.go
index accc4d3..3a7ec6e 100644
--- a/android/makevars.go
+++ b/android/makevars.go
@@ -153,7 +153,7 @@
 func (s *makeVarsSingleton) writeVars(vars []makeVarsVariable) []byte {
 	buf := &bytes.Buffer{}
 
-	fmt.Fprintln(buf, `# Autogenerated file
+	fmt.Fprint(buf, `# Autogenerated file
 
 # Compares SOONG_$(1) against $(1), and warns if they are not equal.
 #
@@ -201,7 +201,7 @@
 		fmt.Fprintf(buf, "$(eval $(call soong-compare-var,%s,%s,my_check_failed := true))\n\n", v.name, sort)
 	}
 
-	fmt.Fprintln(buf, `
+	fmt.Fprint(buf, `
 ifneq ($(my_check_failed),false)
   $(error Soong variable check failed)
 endif