powerpc: Make load_up_fpu and load_up_altivec callable

Make load_up_fpu and load_up_altivec callable so they can be reused by
the VSX code.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 821e152..8a2b3d6 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -85,7 +85,7 @@
 #endif /* CONFIG_SMP */
 	/* restore registers and return */
 	/* we haven't used ctr or xer or lr */
-	b	fast_exception_return
+	blr
 
 /*
  * giveup_fpu(tsk)