funcs: defer close file in funcs

Files opened by these two functions were not being closed,
leaking file descriptors. Close files that were opened when the
function exist.

internal/lang/funcs/crypto.go

@@ -248,6 +248,7 @@ func makeFileHashFunction(baseDir string, hf func() hash.Hash, enc func([]byte)
 			if err != nil {
 				return cty.UnknownVal(cty.String), err
 			}
+			defer f.Close()
 
 			h := hf()
 			_, err = io.Copy(h, f)

internal/lang/funcs/filesystem.go

@@ -377,6 +377,7 @@ func readFileBytes(baseDir, path string) ([]byte, error) {
 		}
 		return nil, err
 	}
+	defer f.Close()
 
 	src, err := ioutil.ReadAll(f)
 	if err != nil {