opcodes/riscv-dis.c: Use bool type whenever possible

Before changing the core disassembler, we take care of minor code clarity
issues and improve readability.

This commit replaces uses of int with bool whenever possible.

opcodes/ChangeLog:

	* riscv-dis.c (no_aliases) Change type to bool.
	(set_default_riscv_dis_options): Use boolean.
	(parse_riscv_dis_option_without_args): Likewise.
	(riscv_disassemble_insn): Use boolean keywords.

opcodes/riscv-dis.c

@@ -71,7 +71,7 @@ static const char * const *riscv_gpr_names;
 static const char * const *riscv_fpr_names;
 
 /* If set, disassemble as most general instruction.  */
-static int no_aliases;
+static bool no_aliases = false;
 
 
 /* Set default RISC-V disassembler options.  */
@@ -81,7 +81,7 @@ set_default_riscv_dis_options (void)
 {
   riscv_gpr_names = riscv_gpr_names_abi;
   riscv_fpr_names = riscv_fpr_names_abi;
-  no_aliases = 0;
+  no_aliases = false;
 }
 
 /* Parse RISC-V disassembler option (without arguments).  */
@@ -90,7 +90,7 @@ static bool
 parse_riscv_dis_option_without_args (const char *option)
 {
   if (strcmp (option, "no-aliases") == 0)
-    no_aliases = 1;
+    no_aliases = true;
   else if (strcmp (option, "numeric") == 0)
     {
       riscv_gpr_names = riscv_gpr_names_numeric;
@@ -645,7 +645,7 @@ static int
 riscv_disassemble_insn (bfd_vma memaddr, insn_t word, disassemble_info *info)
 {
   const struct riscv_opcode *op;
-  static bool init = 0;
+  static bool init = false;
   static const struct riscv_opcode *riscv_hash[OP_MASK_OP + 1];
   struct riscv_private_data *pd;
   int insnlen;
@@ -659,7 +659,7 @@ riscv_disassemble_insn (bfd_vma memaddr, insn_t word, disassemble_info *info)
 	if (!riscv_hash[OP_HASH_IDX (op->match)])
 	  riscv_hash[OP_HASH_IDX (op->match)] = op;
 
-      init = 1;
+      init = true;
     }
 
   if (info->private_data == NULL)