powerpc/64: Remove redundant instruction in interrupt replay

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/entry_64.S

@@ -971,7 +971,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	bne	1f
 	addi	r3,r1,STACK_FRAME_OVERHEAD;
 	bl	doorbell_exception
-	b	ret_from_except
 #endif /* CONFIG_PPC_DOORBELL */
 1:	b	ret_from_except /* What else to do here ? */