util/StringUtil: rename strchug_fast_c() to strchug_fast()

Overload the name.

src/util/StringUtil.cxx

@@ -24,7 +24,7 @@
 #include <assert.h>
 
 const char *
-strchug_fast_c(const char *p)
+strchug_fast(const char *p)
 {
 	while (*p != 0 && g_ascii_isspace(*p))
 		++p;

src/util/StringUtil.hxx

@@ -31,16 +31,13 @@
  */
 gcc_pure
 const char *
-strchug_fast_c(const char *p);
+strchug_fast(const char *p);
 
-/**
- * Same as strchug_fast_c(), but works with a writable pointer.
- */
 gcc_pure
 static inline char *
 strchug_fast(char *p)
 {
-	return const_cast<char *>(strchug_fast_c(p));
+	return const_cast<char *>(strchug_fast((const char *)p));
 }
 
 /**