Journal: fix validVarName validation when var starts with _

the validVarName function tries to test for variables starting with an
underscore but there's a missing set of parentheses.

Fixes #284

Author: GraveRaven

journal/journal.go

@@ -144,7 +144,7 @@ func validVarName(name string) bool {
 
 	valid := name[0] != '_'
 	for _, c := range name {
-		valid = valid && ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || c == '_'
+		valid = valid && (('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || c == '_')
 	}
 	return valid
 }

journal/journal_test.go

@@ -35,6 +35,10 @@ func TestValidaVarName(t *testing.T) {
 			"test",
 			false,
 		},
+		{
+			"_TEST",
+			false,
+		},
 	}
 
 	for _, tt := range testCases {