lib: cleanup validation

Used the `validateInteger()` validator to cleanup validation and keep
consistency.

Author: VoltrexKeyva

lib/internal/tty.js

@@ -34,6 +34,8 @@ const {
   ERR_OUT_OF_RANGE
 } = require('internal/errors').codes;
 
+const { validateInteger } = require('internal/validators');
+
 let OSRelease;
 
 const COLORS_2 = 1;
@@ -220,14 +222,9 @@ function hasColors(count, env) {
       (count === undefined || (typeof count === 'object' && count !== null))) {
     env = count;
     count = 16;
-  } else {
-    if (typeof count !== 'number') {
-      throw new ERR_INVALID_ARG_TYPE('count', 'number', count);
-    }
-    if (count < 2) {
-      throw new ERR_OUT_OF_RANGE('count', '>= 2', count);
-    }
-  }
+  } else
+    validateInteger(count, 'count', 2);
+
   return count <= 2 ** getColorDepth(env);
 }