Fix building of strace for MIPS.

diff -ur strace-4.5.15/signal.c strace-4.5.15-patched/signal.c

--- strace-4.5.15/signal.c	2007-01-11 16:08:38.000000000 -0600

+++ strace-4.5.15-patched/signal.c	2007-02-06 20:49:34.714320249 -0600

@@ -1440,7 +1440,7 @@

 	  	tcp->u_rval = tcp->u_error = 0;

 		if(tcp->u_arg[0] == 0)

 		  	return 0;

-		tcp->auxstr = sprintsigmask("mask now ", tcp->u_arg[1]);

+		tcp->auxstr = sprintsigmask("mask now ", tcp->u_arg[1], 0);

 		return RVAL_NONE | RVAL_STR;

 	}

 	return 0;