elf_ops.h: Don't truncate name of the ROM blobs we create

elf_ops.h: Don't truncate name of the ROM blobs we create

Currently the load_elf code assembles the ROM blob name into a
local 128 byte fixed-size array. Use g_strdup_printf() instead so
that we don't truncate the pathname if it happens to be long.
(This matters mostly for monitor 'info roms' output and for the
error messages if ROM blobs overlap.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201129203923.10622-4-peter.maydell@linaro.org