KVM: riscv: selftests: Use the existing RISCV_FENCE macro in rseq-riscv.h

To avoid redefinition issues with RISCV_FENCE, directly reference
the existing macro in `rseq-riscv.h`.

Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Signed-off-by: Dong Yang <dayss1224@gmail.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/85e5e51757c9289ca463fbc4ba6d22f9c9db791b.1756710918.git.dayss1224@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>

Author: zcxGGmu

tools/testing/selftests/rseq/rseq-riscv.h

@@ -8,6 +8,7 @@
  * exception when executed in all modes.
  */
 #include <endian.h>
+#include <asm/fence.h>
 
 #if defined(__BYTE_ORDER) ? (__BYTE_ORDER == __LITTLE_ENDIAN) : defined(__LITTLE_ENDIAN)
 #define RSEQ_SIG   0xf1401073  /* csrr mhartid, x0 */
@@ -24,8 +25,6 @@
 #define REG_L	__REG_SEL("ld ", "lw ")
 #define REG_S	__REG_SEL("sd ", "sw ")
 
-#define RISCV_FENCE(p, s) \
-	__asm__ __volatile__ ("fence " #p "," #s : : : "memory")
 #define rseq_smp_mb()	RISCV_FENCE(rw, rw)
 #define rseq_smp_rmb()	RISCV_FENCE(r, r)
 #define rseq_smp_wmb()	RISCV_FENCE(w, w)