x86_32: introduce restore_fpu_checking()

Impact: cleanup, prepare FPU code unificaton

Like on x86_64, return an error from restore_fpu and kill the task
if it fails.

Also rename restore_fpu to restore_fpu_checking which allows ifdefs
to be removed in math_state_restore().

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a1d2883..d696145 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -839,9 +839,6 @@
 	}
 
 	clts();				/* Allow maths ops (or we recurse) */
-#ifdef CONFIG_X86_32
-	restore_fpu(tsk);
-#else
 	/*
 	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
 	 */
@@ -850,7 +847,7 @@
 		force_sig(SIGSEGV, tsk);
 		return;
 	}
-#endif
+
 	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */
 	tsk->fpu_counter++;
 }