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/ereader_screen.c

@@ -240,7 +240,7 @@ static bool32 sub_81D5064(u16 *arg0, u16 arg1)
         *arg0 = 0;
         return TRUE;
     }
-    
+
     return FALSE;
 }