[SDK] Minor improvements to CRT, RTL, and headers

Signed-off-by: Quinn Stephens <quinn@osmora.org>

SDK/CRT/STRING/wstr.c

@@ -24,7 +24,9 @@ wcslen (
     const wchar_t *ptr;
 
     ptr = str;
-    while (*ptr++);
+    while (*ptr) {
+        ptr++;
+    }
 
     return ptr - str;
 }
@@ -36,15 +38,14 @@ wcsnlen (
     )
 
 {
-    size_t len;
+    const wchar_t *ptr;
 
-    len = 0;
-    while (len < maxlen && *str) {
-        len++;
-        str++;
+    ptr = str;
+    while (maxlen-- && *ptr) {
+        ptr++;
     }
 
-    return len;
+    return ptr - str;
 }
 
 int