target/riscv/vector_helper.c: Remove the check for extra tail elements

target/riscv/vector_helper.c: Remove the check for extra tail elements

Commit 752614cab8e6 ("target/riscv: rvv: Add tail agnostic for vector
load / store instructions") added an extra check for LMUL fragmentation,
intended for setting the "rest tail elements" in the last register for a
segment load insn.

Actually, the max_elements derived in vext_ld*() won't be a fraction of
vector register size, since the lmul encoded in desc is emul, which has
already been adjusted to 1 for LMUL fragmentation case by vext_get_emul()
in trans_rvv.c.inc, for ld_stride(), ld_us(), ld_index() and ldff().

Besides, vext_get_emul() has also taken EEW/SEW into consideration, so no
need to call vext_get_total_elems() which would base on the emul to derive
another emul, the second emul would be incorrect when esz differs from sew.

Thus this patch removes the check for extra tail elements.

Fixes: 752614cab8e6 ("target/riscv: rvv: Add tail agnostic for vector load / store instructions")
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-Id: <20230607091646.4049428-1-xiao.w.wang@intel.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>