RISC-V: Fix misspelled term builtin in error message

RISC-V: Fix misspelled term builtin in error message

This patch would like to fix below misspelled term in error message.

../../gcc/config/riscv/riscv-vector-builtins.cc:4592:16: error:
misspelled term 'builtin function' in format; use 'built-in function' instead [-Werror=format-diag]
 4592 |               "builtin function %qE requires the V ISA extension", exp);

The below tests are passed for this patch.
* The riscv regression test on rvv.exp and riscv.exp.

gcc/ChangeLog:

	* config/riscv/riscv-vector-builtins.cc (expand_builtin): Take
	the term built-in over builtin.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/base/target_attribute_v_with_intrinsic-7.c:
	Adjust test dg-error.
	* gcc.target/riscv/rvv/base/target_attribute_v_with_intrinsic-8.c:
	Ditto.

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