translate-all: delete prototype for non-existent function

Missed in commit 3a808cc4Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

translate-all.h

@@ -21,7 +21,6 @@
 
 /* translate-all.c */
 void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len);
-void cpu_unlink_tb(CPUState *cpu);
 void tb_check_watchpoint(CPUState *cpu);
 
 #endif /* TRANSLATE_ALL_H */