Fix typo in "pg_xlogdump --help" and error message.

Fujii Masao and me.

contrib/pg_xlogdump/pg_xlogdump.c

@@ -393,7 +393,7 @@ usage(void)
 	printf("                         (default: ./pg_xlog)\n");
 	printf("  -r, --rmgr=RMGR        only show records generated by resource manager RMGR\n");
 	printf("                         use --rmgr=list to list valid resource manager names\n");
-	printf("  -s, --start=RECPTR     stop reading at log position RECPTR\n");
+	printf("  -s, --start=RECPTR     start reading at log position RECPTR\n");
 	printf("  -t, --timeline=TLI     timeline from which to read log records\n");
 	printf("                         (default: 1 or the value used in STARTSEG)\n");
 	printf("  -x, --xid=XID          only show records with TransactionId XID\n");
@@ -512,7 +512,7 @@ main(int argc, char **argv)
 			case 's':
 				if (sscanf(optarg, "%X/%X", &xlogid, &xrecoff) != 2)
 				{
-					fprintf(stderr, "%s: could not parse end log position \"%s\"\n",
+					fprintf(stderr, "%s: could not parse start log position \"%s\"\n",
 							progname, optarg);
 					goto bad_argument;
 				}