Fix for Coverity CID#2: false bug, but still a problem.

Analysis:
internal_errorf(int, fmt, ...) was only a __dead function if the int argument
was non-0, which the Prevent probably was unable to follow. Change all uses of
internal_errorf(0, fmt, ...) to internal_warningf(fmt, ...); change the pro-
totype of internal_errorf() to internal_errorf(fmt, ...) and all remaining
uses remove the non-0 int argument; add __dead to internal_errorf() proto;
flesh out guts of internal_errorf() and internal_warningf() into a new local
function for optimisation purposes.

Some whitespace cleanup and dead code removal (return after internal_errorf(1))

tree.c

@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.9 2007/03/04 03:04:28 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.10 2007/05/13 17:51:24 tg Exp $");
 
 #define INDENT	4
 
@@ -519,7 +519,7 @@ wdscan(const char *wp, int c)
 				nest--;
 			break;
 		default:
-			internal_errorf(0,
+			internal_warningf(
 			    "wdscan: unknown char 0x%x (carrying on)",
 			    wp[-1]);
 		}