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)

src/thread/pthread/SDL_syscond.c

@@ -48,7 +48,7 @@ SDL_CreateCond(void)
             cond = NULL;
         }
     }
-    return (cond);
+    return cond;
 }
 
 /* Destroy a condition variable */
@@ -67,7 +67,7 @@ SDL_CondSignal(SDL_cond * cond)
 {
     int retval;
 
-    if (!cond) {
+    if (cond == NULL) {
         return SDL_InvalidParamError("cond");
     }
 
@@ -84,7 +84,7 @@ SDL_CondBroadcast(SDL_cond * cond)
 {
     int retval;
 
-    if (!cond) {
+    if (cond == NULL) {
         return SDL_InvalidParamError("cond");
     }
 
@@ -104,7 +104,7 @@ SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
 #endif
     struct timespec abstime;
 
-    if (!cond) {
+    if (cond == NULL) {
         return SDL_InvalidParamError("cond");
     }
 
@@ -147,7 +147,7 @@ SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
 int
 SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
 {
-    if (!cond) {
+    if (cond == NULL) {
         return SDL_InvalidParamError("cond");
     } else if (pthread_cond_wait(&cond->cond, &mutex->id) != 0) {
         return SDL_SetError("pthread_cond_wait() failed");

src/thread/pthread/SDL_sysmutex.c

@@ -64,7 +64,7 @@ SDL_CreateMutex(void)
     } else {
         SDL_OutOfMemory();
     }
-    return (mutex);
+    return mutex;
 }
 
 void

src/thread/pthread/SDL_syssem.c

@@ -72,7 +72,7 @@ SDL_SemTryWait(SDL_sem * sem)
 {
     int retval;
 
-    if (!sem) {
+    if (sem == NULL) {
         return SDL_InvalidParamError("sem");
     }
     retval = SDL_MUTEX_TIMEDOUT;
@@ -87,7 +87,7 @@ SDL_SemWait(SDL_sem * sem)
 {
     int retval;
 
-    if (!sem) {
+    if (sem == NULL) {
         return SDL_InvalidParamError("sem");
     }
 
@@ -114,7 +114,7 @@ SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
     Uint32 end;
 #endif
 
-    if (!sem) {
+    if (sem == NULL) {
         return SDL_InvalidParamError("sem");
     }
 
@@ -194,7 +194,7 @@ SDL_SemPost(SDL_sem * sem)
 {
     int retval;
 
-    if (!sem) {
+    if (sem == NULL) {
         return SDL_InvalidParamError("sem");
     }
 

src/thread/pthread/SDL_systhread.c

@@ -187,7 +187,7 @@ SDL_SYS_SetupThread(const char *name)
 SDL_threadID
 SDL_ThreadID(void)
 {
-    return ((SDL_threadID) pthread_self());
+    return (SDL_threadID)pthread_self();
 }
 
 int