sim: m32c: opc2c: remove unused vlist variable

sim: m32c: opc2c: remove unused vlist variable

When building with AddressSanitizer, sim/m32c fails with:

./opc2c -l r8c.out /home/simark/src/binutils-gdb/sim/m32c/r8c.opc > r8c.c
sim_log: r8c.out

=================================================================
==3919390==ERROR: LeakSanitizer: detected memory leaks

    Direct leak of 4 byte(s) in 1 object(s) allocated from:
        #0 0x7ffff7677459 in __interceptor_malloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:145
        #1 0x55555555b3df in main /home/simark/src/binutils-gdb/sim/m32c/opc2c.c:658
        #2 0x7ffff741fb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)

Fix the leak in main by removing the vlist variable, which seems unused.