fix 6a line number bug -

was incrementing lineno twice for
the \n after a // comment.

R=r
DELTA=3  (0 added, 2 deleted, 1 changed)
OCL=21984
CL=22021

src/cmd/cc/lexbody

@@ -462,10 +462,8 @@ l1:
 		if(c1 == '/') {
 			for(;;) {
 				c = GETC();
-				if(c == '\n') {
-					lineno++;
+				if(c == '\n')
 					goto l1;
-				}
 				if(c == EOF) {
 					yyerror("eof in comment");
 					errorexit();