libdtrace: Fix dt_print_sym() not printing symbols in non-oformat mode

dt_print_sym() fills the symbol string via snprintf() in non-oformat
mode but the guarding `dtp->dt_oformat != 0 &&` for the dt_printf()
call causes the symbol is computed but never emitted.

This fixes tests:

- common.profile-n.t_dtrace_contrib.tst_sym_ksh
- common.profile-n.t_dtrace_contrib.tst_func_ksh

Reviewed by:	markj
Fixes:		93f27766a7 ("dtrace: Add the 'oformat' libdtrace option")
MFC after:	3 days
Event:		Halifax Hackathon 202606
Location:	Room 208, Computer Science Building, Dalhousie University
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D57895

(cherry picked from commit 8e61d8707f)

cddl/contrib/opensolaris/lib/libdtrace/common/dt_consume.c

@@ -2143,7 +2143,7 @@ dt_print_sym(dtrace_hdl_t *dtp, FILE *fp, const char *format, caddr_t addr)
 		}
 	}
 
-	if (dtp->dt_oformat != 0 && dt_printf(dtp, fp, format, c) < 0)
+	if (!dtp->dt_oformat && dt_printf(dtp, fp, format, c) < 0)
 		return (-1);
 
 	return (0);