fix undefined function error.

before:
	mainstart: undefined: main·init in mainstart
	mainstart: branch out of range in mainstart
	(95)    CALL    ,0(PC) [main·init]
	mainstart: undefined: main·main in mainstart
	mainstart: branch out of range in mainstart
	(97)    CALL    ,0(PC) [main·main]
	mainstart: doasm: notfound from=6f to=6f (95)    CALL    ,
	mainstart: doasm: notfound from=6f to=6f (97)    CALL    ,
	mainstart: doasm: notfound from=6f to=6f (95)    CALL    ,
	mainstart: doasm: notfound from=6f to=6f (97)    CALL    ,
	mainstart: doasm: notfound from=6f to=6f (95)    CALL    ,
	mainstart: doasm: notfound from=6f to=6f (97)    CALL    ,

after:
	mainstart: undefined: main·init in mainstart
	mainstart: undefined: main·main in mainstart

R=r
DELTA=7  (1 added, 0 deleted, 6 changed)
OCL=31555
CL=31555

src/cmd/5l/pass.c

@@ -343,10 +343,10 @@ patch(void)
 			s = p->to.sym;
 			switch(s->type) {
 			default:
-				diag("undefined: %s\n%P", s->name, p);
+				diag("undefined: %s", s->name);
 				s->type = STEXT;
 				s->value = vexit;
-				break;
+				continue;	// avoid more error messages
 			case STEXT:
 				p->to.offset = s->value;
 				p->to.type = D_BRANCH;

src/cmd/6l/pass.c

@@ -377,10 +377,11 @@ patch(void)
 					Bprint(&bso, "%s calls %s\n", TNAME, s->name);
 				switch(s->type) {
 				default:
-					diag("undefined: %s in %s", s->name, TNAME);
+					/* diag prints TNAME first */
+					diag("undefined: %s", s->name);
 					s->type = STEXT;
 					s->value = vexit;
-					break;	/* or fall through to set offset? */
+					continue;	// avoid more error messages
 				case STEXT:
 					p->to.offset = s->value;
 					break;

src/cmd/8l/pass.c

@@ -346,10 +346,10 @@ patch(void)
 				switch(s->type) {
 				default:
 					/* diag prints TNAME first */
-					diag("%s is undefined", s->name);
+					diag("undefined: %s", s->name);
 					s->type = STEXT;
 					s->value = vexit;
-					break;	/* or fall through to set offset? */
+					continue;	// avoid more error messages
 				case STEXT:
 					p->to.offset = s->value;
 					break;