target-s390x: Clean up ENV_GET_CPU() usage

Commits f606604f1c10b60ef294f1b9b229426521a365e3,
2c17449b3022ca9623c4a7e2a504a4150ac4ad30 and
5ce5944dc0ffdc43c11b5cad11e526f699aabe4c added usages of ENV_GET_CPU()
macro in target-specific code.

Use s390_env_get_cpu() instead.

Cc: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-s390x/helper.c b/target-s390x/helper.c
index aa537e1..0bae0a3 100644
--- a/target-s390x/helper.c
+++ b/target-s390x/helper.c
@@ -138,7 +138,7 @@
 static void trigger_prot_fault(CPUS390XState *env, target_ulong vaddr,
                                uint64_t mode)
 {
-    CPUState *cs = ENV_GET_CPU(env);
+    CPUState *cs = CPU(s390_env_get_cpu(env));
     int ilen = ILEN_LATER_INC;
     int bits = trans_bits(env, mode) | 4;
 
@@ -152,7 +152,7 @@
 static void trigger_page_fault(CPUS390XState *env, target_ulong vaddr,
                                uint32_t type, uint64_t asc, int rw)
 {
-    CPUState *cs = ENV_GET_CPU(env);
+    CPUState *cs = CPU(s390_env_get_cpu(env));
     int ilen = ILEN_LATER;
     int bits = trans_bits(env, asc);
 
@@ -172,7 +172,7 @@
                               uint64_t asc, uint64_t asce, int level,
                               target_ulong *raddr, int *flags, int rw)
 {
-    CPUState *cs = ENV_GET_CPU(env);
+    CPUState *cs = CPU(s390_env_get_cpu(env));
     uint64_t offs = 0;
     uint64_t origin;
     uint64_t new_asce;