Simplify three copyright headers.

There's no reason to have multiple years in our own copyright headers,
and given the stupidity of our NOTICE file generation, it just creates
more junk.

Change-Id: I065a3811c2e2584e3b649a18ad9460286bc72b92

libc/arch-arm/bionic/__bionic_clone.S

 /*
- * Copyright (C) 2008-2010 The Android Open Source Project
+ * Copyright (C) 2008 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without

libc/arch-mips/bionic/setjmp.S

 /*
- * Copyright (C) 2014-2015 The Android Open Source Project
+ * Copyright (C) 2014 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without

linker/linker_debug.h

 /*
- * Copyright (C) 2008-2010 The Android Open Source Project
+ * Copyright (C) 2008 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without