Removed trailing spaces in the most relevant files

Command used for the job:
egrep -rl ' $' --include *.c --include *.h --include  *.s --include  *.inc --include  *.txt *  | xargs sed -i 's/\s\+$//g'

Credits to Grant Murphy from Stack Overflow.

src/battle_anim_sound_tasks.c

@@ -349,7 +349,7 @@ void SoundTask_PlaySE2WithPanning(u8 taskId)
     DestroyAnimVisualTask(taskId);
 }
 
-// Adjusts panning and assigns it to gAnimCustomPanning. Doesnt play sound. 
+// Adjusts panning and assigns it to gAnimCustomPanning. Doesnt play sound.
 // Used by Confuse Ray and Will-O-Wisp (see uses of gAnimCustomPanning)
 void SoundTask_AdjustPanningVar(u8 taskId)
 {
@@ -381,7 +381,7 @@ static void SoundTask_AdjustPanningVar_Step(u8 taskId)
         u16 oldPan;
         gTasks[taskId].data[10] = 0;
         oldPan = gTasks[taskId].data[11];
-        gTasks[taskId].data[11] = panIncrement + oldPan; 
+        gTasks[taskId].data[11] = panIncrement + oldPan;
         gTasks[taskId].data[11] = KeepPanInRange(gTasks[taskId].data[11], oldPan);
     }