[POWERPC] Remove unused do_signal export

do_signal is never used in modular code (obviously), and no other
architecture exports it either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/ppc_ksyms.c

@@ -67,7 +67,6 @@ EXPORT_SYMBOL(ISA_DMA_THRESHOLD);
 EXPORT_SYMBOL(DMA_MODE_READ);
 EXPORT_SYMBOL(DMA_MODE_WRITE);
 
-EXPORT_SYMBOL(do_signal);
 EXPORT_SYMBOL(transfer_to_handler);
 EXPORT_SYMBOL(do_IRQ);
 EXPORT_SYMBOL(machine_check_exception);

arch/ppc/kernel/ppc_ksyms.c

@@ -64,7 +64,6 @@ extern unsigned long mm_ptov (unsigned long paddr);
 
 EXPORT_SYMBOL(clear_pages);
 EXPORT_SYMBOL(clear_user_page);
-EXPORT_SYMBOL(do_signal);
 EXPORT_SYMBOL(transfer_to_handler);
 EXPORT_SYMBOL(do_IRQ);
 EXPORT_SYMBOL(machine_check_exception);