Clarify that FENCE + remote FENCE.I is insufficient for local hart (r…

…iscv#503)

This sequence only synchronises the remote harts; the local hart still
needs to perform a normal FENCE.I.

src/zifencei.tex

@@ -92,7 +92,7 @@ \chapter{``Zifencei'' Instruction-Fetch Fence, Version 2.0}
 hart.  FENCE.I does {\em not} ensure that other RISC-V harts'
 instruction fetches will observe the local hart's stores in a
 multiprocessor system. To make a store to instruction memory visible
-to all RISC-V harts, the writing hart has to execute a data FENCE
+to all RISC-V harts, the writing hart also has to execute a data FENCE
 before requesting that all remote RISC-V harts execute a FENCE.I.
 
 The unused fields in the FENCE.I instruction, {\em imm[11:0]}, {\em rs1}, and