powerpc: unexport flush_icache_user_range

flush_icache_user_range is only used by copy_to_user_page, which is only
used by core VM code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: http://lkml.kernel.org/r/20200515143646.3857579-4-hch@lst.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/mm/mem.c

@@ -586,7 +586,6 @@ void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 	flush_icache_range(maddr, maddr + len);
 	kunmap(page);
 }
-EXPORT_SYMBOL(flush_icache_user_range);
 
 /*
  * System memory should not be in /proc/iomem but various tools expect it