pledge support for renice

[Theo Buehler]

renice(1) needs "proc" for {get,set}priority and in addition it needs
"getpw" throughout option parsing for getpwnam and getpwuid.  Drop
"getpw" as soon as possible.

Index: renice.c
===================================================================
RCS file: /var/cvs/src/usr.bin/renice/renice.c,v
retrieving revision 1.18
diff -u -p -r1.18 renice.c
--- renice.c    15 May 2015 19:34:31 -0000      1.18
+++ renice.c    19 Oct 2015 21:21:56 -0000
@@ -55,6 +55,9 @@ main(int argc, char **argv)
        char *ep, *idstr;
        const char *errstr;
 
+       if (pledge("stdio getpw proc", NULL) == -1)
+               err(1, "pledge");
+
        if (argc < 3)
                usage();
 
@@ -144,6 +147,8 @@ main(int argc, char **argv)
                }
                p++;
        }
+       if (pledge("stdio proc", NULL) == -1)
+               err(1, "pledge");
        if (pri_type == RENICE_NONE)
                usage();
        exit(renice(params, p));