tar: work aruond IBM XL C bug

* src/incremen.c (show_snapshot_field_ranges)
(write_directory_file_entry): Use simpler array size expression,
one that evaluates to the same value.  This works around a compiler
bug with IBM XL C.  Problem reported by Yannick Bergeron in
<http://lists.gnu.org/archive/html/bug-tar/2014-01/msg00009.html>.

src/incremen.c

@@ -759,7 +759,7 @@ scan_directory (struct tar_stat_info *st)
 	       entry = dumpdir_next (itr))
 	    {
 	      char *full_name = namebuf_name (nbuf, entry + 1);
-	      
+
 	      if (*entry == 'I') /* Ignored entry */
 		*entry = 'N';
 	      else if (excluded_name (full_name))
@@ -792,7 +792,7 @@ scan_directory (struct tar_stat_info *st)
 			    diag = stat_diag;
 			}
 		    }
-		  
+
 		  if (diag)
 		    {
 		      file_removed_diag (full_name, false, diag);
@@ -806,7 +806,7 @@ scan_directory (struct tar_stat_info *st)
 		      else if (directory->children == ALL_CHILDREN)
 			pd_flag |= PD_FORCE_CHILDREN | ALL_CHILDREN;
 		      *entry = 'D';
-		      
+
 		      stsub.parent = st;
 		      procdir (full_name, &stsub, pd_flag, entry);
 		      restore_parent_fd (&stsub);
@@ -823,7 +823,7 @@ scan_directory (struct tar_stat_info *st)
 		    *entry = 'N';
 		  else
 		    *entry = 'Y';
-		  
+
 		  tar_stat_destroy (&stsub);
 		}
 	    }
@@ -832,7 +832,7 @@ scan_directory (struct tar_stat_info *st)
       else if (directory->tagfile)
 	maketagdumpdir (directory);
     }
-  
+
   namebuf_free (nbuf);
 
   free (dirp);
@@ -1296,8 +1296,8 @@ void
 show_snapshot_field_ranges (void)
 {
   struct field_range const *p;
-  char minbuf[max (SYSINT_BUFSIZE, INT_BUFSIZE_BOUND (intmax_t))];
-  char maxbuf[max (SYSINT_BUFSIZE, INT_BUFSIZE_BOUND (uintmax_t))];
+  char minbuf[SYSINT_BUFSIZE];
+  char maxbuf[SYSINT_BUFSIZE];
 
   printf("This tar's snapshot file field ranges are\n");
   printf ("   (%-15s => [ %s, %s ]):\n\n", "field name", "min", "max");
@@ -1406,7 +1406,7 @@ write_directory_file_entry (void *entry, void *data)
 
   if (DIR_IS_FOUND (directory))
     {
-      char buf[max (SYSINT_BUFSIZE, INT_BUFSIZE_BOUND (intmax_t))];
+      char buf[SYSINT_BUFSIZE];
       char const *s;
 
       s = DIR_IS_NFS (directory) ? "1" : "0";