Cleanup add brace (#6545)

* Add braces after if conditions

* More add braces after if conditions

* Add braces after while() conditions

* Fix compilation because of macro being modified

* Add braces to for loop

* Add braces after if/goto

* Move comments up

* Remove extra () in the 'return ...;' statements

* More remove extra () in the 'return ...;' statements

* More remove extra () in the 'return ...;' statements after merge

* Fix inconsistent patterns are xxx == NULL vs !xxx

* More "{}" for "if() break;"  and "if() continue;"

* More "{}" after if() short statement

* More "{}" after "if () return;" statement

* More fix inconsistent patterns are xxx == NULL vs !xxx

* Revert some modificaion on SDL_RLEaccel.c

* SDL_RLEaccel: no short statement

* Cleanup 'if' where the bracket is in a new line

* Cleanup 'while' where the bracket is in a new line

* Cleanup 'for' where the bracket is in a new line

* Cleanup 'else' where the bracket is in a new line

(cherry picked from commit 6a2200823c to reduce conflicts merging between SDL2 and SDL3)

test/testhittesting.c

@@ -74,8 +74,7 @@ int main(int argc, char **argv)
         return 1;
     }
 
-    while (!done)
-    {
+    while (!done) {
         SDL_Event e;
         int nothing_to_do = 1;
 
@@ -108,7 +107,7 @@ int main(int argc, char **argv)
                     if (e.key.keysym.sym == SDLK_ESCAPE) {
                         done = 1;
                     } else if (e.key.keysym.sym == SDLK_x) {
-                        if (!areas) {
+                        if (areas == NULL) {
                             areas = drag_areas;
                             numareas = SDL_arraysize(drag_areas);
                         } else {