powerpc/inst: Improve readability of get_user_instr() and friends

Remove unneeded line splits.

And remove unneeded local variable initialisation.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fb097fda78cc6852905ef00f8f7bf371b6cc66f7.1621516826.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/inst.h

@@ -8,7 +8,7 @@
 
 #define ___get_user_instr(gu_op, dest, ptr)				\
 ({									\
-	long __gui_ret = 0;						\
+	long __gui_ret;							\
 	u32 __user *__gui_ptr = (u32 __user *)ptr;			\
 	struct ppc_inst __gui_inst;					\
 	unsigned int __prefix, __suffix;				\
@@ -18,8 +18,7 @@
 	if (__gui_ret == 0) {						\
 		if ((__prefix >> 26) == OP_PREFIX) {			\
 			__gui_ret = gu_op(__suffix, __gui_ptr + 1);	\
-			__gui_inst = ppc_inst_prefix(__prefix,		\
-						     __suffix);		\
+			__gui_inst = ppc_inst_prefix(__prefix, __suffix); \
 		} else {						\
 			__gui_inst = ppc_inst(__prefix);		\
 		}							\
@@ -36,11 +35,9 @@
 })
 #endif /* CONFIG_PPC64 */
 
-#define get_user_instr(x, ptr) \
-	___get_user_instr(get_user, x, ptr)
+#define get_user_instr(x, ptr) ___get_user_instr(get_user, x, ptr)
 
-#define __get_user_instr(x, ptr) \
-	___get_user_instr(__get_user, x, ptr)
+#define __get_user_instr(x, ptr) ___get_user_instr(__get_user, x, ptr)
 
 /*
  * Instruction data type for POWER
@@ -75,13 +72,12 @@ static inline u32 ppc_inst_suffix(struct ppc_inst x)
 
 static inline bool ppc_inst_prefixed(struct ppc_inst x)
 {
-	return (ppc_inst_primary_opcode(x) == 1) && ppc_inst_suffix(x) != 0xff;
+	return ppc_inst_primary_opcode(x) == OP_PREFIX && ppc_inst_suffix(x) != 0xff;
 }
 
 static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
 {
-	return ppc_inst_prefix(swab32(ppc_inst_val(x)),
-			       swab32(ppc_inst_suffix(x)));
+	return ppc_inst_prefix(swab32(ppc_inst_val(x)), swab32(ppc_inst_suffix(x)));
 }
 
 static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)