Compare buffered opcodes to current one at the same address

[Rot127]

At https://github.com/rizinorg/rizin/blob/a689f0a86ee7218a12dc7ab5f00ff985d737019f/librz/asm/arch/hexagon/hexagon_arch.c#L780-L782

the asm plugin checks if an instruction at the given address is already buffered and returns it if so.
This can lead to incorrect textual disassembly if the opcode at this address changed and the instruction would be another than before.

The instruction should be disassembled again, if the buffered opcode doesn't match the given one.