moved check_span into namespaces

Author: Sriya Pratipati

libc/src/wchar/wchar_utils.h

@@ -14,6 +14,9 @@
 #include "src/__support/common.h"
 #include "src/__support/macros/attributes.h" // LIBC_INLINE
 
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
+
 bool check_span(wchar_t c, const wchar_t *str) {
   for (int n = 0; str[n]; ++n) {
     if (str[n] == c)
@@ -22,9 +25,6 @@ bool check_span(wchar_t c, const wchar_t *str) {
   return false;
 }
 
-namespace LIBC_NAMESPACE_DECL {
-namespace internal {
-
 // To avoid duplicated code, call this with true for wcscspn and call with false
 // for wcsspn
 LIBC_INLINE size_t inline_wcsspn(const wchar_t *s1, const wchar_t *s2,