[Toybox] [PATCH] fix ps.c build

[enh]

Fix ps.c build.

external/toybox/toys/pending/ps.c:315:21: error: address of array
'field->title' will always evaluate to 'true'
[-Werror,-Wpointer-bool-conversion]
        if (!field->title) strcpy(field->title, typos[field->which]);
            ~~~~~~~~^~~~~

diff --git a/toys/pending/ps.c b/toys/pending/ps.c
index cb0f32c..29111d5 100644
--- a/toys/pending/ps.c
+++ b/toys/pending/ps.c
@@ -312,7 +312,7 @@ void ps_main(void)
           if (j!=2) break;
         }
         if (i == ARRAY_LEN(typos)) error_exit("bad -o %.*s", end-type, type);
-        if (!field->title) strcpy(field->title, typos[field->which]);
+        if (!*field->title) strcpy(field->title, typos[field->which]);
         dlist_add_nomalloc((void *)&TT.fields, (void *)field);
       }
     }

 1429389780.0