KVM: s390: fix instruction interception trace point

trace-cmd fails to parse the instruction interception trace point:
  "Error: expected type 5 but read 4
   failed to read event print fmt for kvm_s390_intercept_instruction"
The result is an unformatted string in the output, with a warning:
  "kvm_s390_intercept_instruction: [FAILED TO PARSE]..."

So let's add parentheses around the instruction parser macro to fix the format
parsing.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/uapi/asm/sie.h

@@ -230,7 +230,7 @@
  * and returns a key, which can be used to find a mnemonic name
  * of the instruction in the icpt_insn_codes table.
  */
-#define icpt_insn_decoder(insn)			\
+#define icpt_insn_decoder(insn) (		\
 	INSN_DECODE_IPA0(0x01, insn, 48, 0xff)	\
 	INSN_DECODE_IPA0(0xaa, insn, 48, 0x0f)	\
 	INSN_DECODE_IPA0(0xb2, insn, 48, 0xff)	\
@@ -239,6 +239,6 @@
 	INSN_DECODE_IPA0(0xe5, insn, 48, 0xff)	\
 	INSN_DECODE_IPA0(0xeb, insn, 16, 0xff)	\
 	INSN_DECODE_IPA0(0xc8, insn, 48, 0x0f)	\
-	INSN_DECODE(insn)
+	INSN_DECODE(insn))
 
 #endif /* _UAPI_ASM_S390_SIE_H */