SDL_iconv_string() defaults to UTF-8

Fixes https://github.com/libsdl-org/SDL/issues/8287

(cherry picked from commit 1375d2049d9fd17cb0d9a47a0e256a42c3188f76)

src/stdlib/SDL_iconv.c

@@ -795,17 +795,13 @@ char *SDL_iconv_string(const char *tocode, const char *fromcode, const char *inb
     size_t outbytesleft;
     size_t retCode = 0;
 
-    cd = SDL_iconv_open(tocode, fromcode);
-    if (cd == (SDL_iconv_t)-1) {
-        /* See if we can recover here (fixes iconv on Solaris 11) */
-        if (tocode == NULL || !*tocode) {
-            tocode = "UTF-8";
-        }
-        if (fromcode == NULL || !*fromcode) {
-            fromcode = "UTF-8";
-        }
-        cd = SDL_iconv_open(tocode, fromcode);
+    if (tocode == NULL || !*tocode) {
+        tocode = "UTF-8";
+    }
+    if (fromcode == NULL || !*fromcode) {
+        fromcode = "UTF-8";
     }
+    cd = SDL_iconv_open(tocode, fromcode);
     if (cd == (SDL_iconv_t)-1) {
         return NULL;
     }