bin/49169: Patch to make certain error messages in date(1) more specific and simplify it a bit

[dhgutteridge%sympatico.ca@localhost]

>Number:         49169
>Category:       bin
>Synopsis:       Patch to make certain error messages in date(1) more specific 
>and simplify it a bit
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Sun Aug 31 20:15:00 +0000 2014
>Originator:     David H. Gutteridge
>Release:        HEAD
>Organization:
>Environment:
n/a
>Description:
I've attached a patch to this PR that makes a couple of error
messages more specific and reduces the number of functions, since two
were effectively duplicates, and one seems unnecessary given it just
wraps a call to errx().

>How-To-Repeat:
Make fat-fingered typos while using date(1).
>Fix:
--- date.c.orig 2011-08-27 23:01:15.000000000 -0400
+++ date.c      2014-06-01 02:09:14.000000000 -0400
@@ -66,8 +66,6 @@
 static time_t tval;
 static int aflag, jflag, rflag, nflag;
 
-__dead static void badformat(void);
-__dead static void badtime(void);
 __dead static void badvalue(const char *);
 static void setthetime(const char *);
 __dead static void usage(void);
@@ -162,20 +160,6 @@
 }
 
 static void
-badformat(void)
-{
-       warnx("illegal time format");
-       usage();
-}
-
-static void
-badtime(void)
-{
-       errx(EXIT_FAILURE, "illegal time");
-       /* NOTREACHED */
-}
-
-static void
 badvalue(const char *param)
 {
        warnx("invalid %s supplied", param);
@@ -201,7 +185,7 @@
                        dot = t;
                        continue;
                }
-               badformat();
+               badvalue("general format");
        }
 
        if ((lt = localtime(&tval)) == NULL)
@@ -212,7 +196,7 @@
        if (dot != NULL) {                      /* .ss */
                len = strlen(dot);
                if (len != 3)
-                       badformat();
+                       badvalue("seconds");
                ++dot;
                lt->tm_sec = ATOI2(dot);
                if (lt->tm_sec > 61)
@@ -227,7 +211,7 @@
        case 12:                                /* cc */
                lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
                if (lt->tm_year < 0)
-                       badtime();
+                       badvalue("century");
                yearset = 1;
                /* FALLTHROUGH */
        case 10:                                /* yy */
@@ -293,12 +277,12 @@
                        break;
                /* FALLTHROUGH */
        default:
-               badformat();
+               badvalue("general format");
        }
 
        /* convert broken-down time to UTC clock time */
        if ((new_time = mktime(lt)) == -1)
-               badtime();
+               errx(EXIT_FAILURE, "illegal time");
 
        /* if jflag is set, don't actually change the time, just return */
        if (jflag) {