x86/fpu: Remove second definition of fpu in __fpu__restore_sig()

Commit:

  c5bedc68

 ("x86/fpu: Get rid of PF_USED_MATH usage, convert it to fpu->fpstate_active")

introduced the 'fpu' variable at top of __restore_xstate_sig(),
which now shadows the other definition:

  arch/x86/kernel/fpu/signal.c:318:28: warning: symbol 'fpu' shadows an earlier one
  arch/x86/kernel/fpu/signal.c:271:20: originally declared here

Remove the shadowed definition of 'fpu', as the two definitions are the same.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c5bedc68

 ("x86/fpu: Get rid of PF_USED_MATH usage, convert it to fpu->fpstate_active")
Link: http://lkml.kernel.org/r/20181016202525.29437-3-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>