RISC-V: Remove unnecessary asm check for rounding autovec

RISC-V: Remove unnecessary asm check for rounding autovec

The vsetvl asm check is unnecessary for the rounding function autovec.
These rounding test cases should focus on the rounding insn sequence.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/unop/bswap16-0.c: Remove the
	vsetvl check.
	* gcc.target/riscv/rvv/autovec/unop/math-ceil-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-ceil-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-ceil-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-ceil-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-floor-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-floor-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-floor-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-floor-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-iceil-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-ifloor-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-irint-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-iround-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lceil-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lceil-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lfloor-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lfloor-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-llceil-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-llfloor-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-llrint-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-llround-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lrint-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lrint-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lround-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-lround-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-nearbyint-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-nearbyint-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-nearbyint-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-nearbyint-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-rint-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-rint-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-rint-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-rint-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-round-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-round-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-round-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-round-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-roundeven-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-roundeven-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-roundeven-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-roundeven-3.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-trunc-0.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-trunc-1.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-trunc-2.c: Ditto.
	* gcc.target/riscv/rvv/autovec/unop/math-trunc-3.c: Ditto.

Signed-off-by: Pan Li <pan2.li@intel.com>