libsframe: use uint8_t for return type of sframe_fre_get_base_reg_id

Use a more appropriate data type.

include/
	* sframe-api.h (sframe_fre_get_base_reg_id): Use uint8_t as
	return type.
libsframe/
	* sframe-dump.c (dump_sframe_func_with_fres): Use uint8_t type
	for base reg id.
	* sframe.c (sframe_fre_get_base_reg_id): Use uin8_t as return
	type.

include/sframe-api.h

@@ -173,7 +173,7 @@ extern void
 dump_sframe (sframe_decoder_ctx *decoder, uint64_t addr);
 
 /* Get the base reg id from the FRE info.  Sets errp if fails.  */
-extern unsigned int
+extern uint8_t
 sframe_fre_get_base_reg_id (sframe_frame_row_entry *fre, int *errp);
 
 /* Get the CFA offset from the FRE.  If the offset is invalid, sets errp.  */

libsframe/sframe-dump.c

@@ -105,7 +105,7 @@ dump_sframe_func_with_fres (sframe_decoder_ctx *sfd_ctx,
   int32_t cfa_offset = 0;
   int32_t fp_offset = 0;
   int32_t ra_offset = 0;
-  unsigned int base_reg_id = 0;
+  uint8_t base_reg_id = 0;
   int err[3] = {0, 0, 0};
 
   sframe_frame_row_entry fre;

libsframe/sframe.c

@@ -618,7 +618,7 @@ sframe_calc_fre_type (size_t func_size)
 
 /* Get the base reg id from the FRE info.  Set errp if failure.  */
 
-unsigned int
+uint8_t
 sframe_fre_get_base_reg_id (sframe_frame_row_entry *fre, int *errp)
 {
   if (fre == NULL)