powerpc/ftrace: Simplify expected_nop_sequence()

Avoid ifdefs around expected_nop_sequence().

While at it make it a bool.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/305d22472f1f92127fba09692df6bb5d079a8cd0.1652074503.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/trace/ftrace.c

@@ -390,24 +390,14 @@ int ftrace_make_nop(struct module *mod,
  * They should effectively be a NOP, and follow formal constraints,
  * depending on the ABI. Return false if they don't.
  */
-#ifdef CONFIG_PPC64_ELF_ABI_V1
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
-{
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) ||
-	    !ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC)))
-		return 0;
-	return 1;
-}
-#else
-static int
-expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
+static bool expected_nop_sequence(void *ip, ppc_inst_t op0, ppc_inst_t op1)
 {
-	if (!ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP())))
-		return 0;
-	return 1;
+	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_BRANCH(8))) &&
+		       ppc_inst_equal(op1, ppc_inst(PPC_INST_LD_TOC));
+	else
+		return ppc_inst_equal(op0, ppc_inst(PPC_RAW_NOP()));
 }
-#endif
 
 static int
 __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)