dpkg: Uppercase and namespace color cycle enum values

The current names are way too generic, and prone to collide with actual
color variables or similar.

src/depcon.c

@@ -165,9 +165,9 @@ findbreakcyclerecursive(struct pkginfo *pkg, struct cyclesofarlink *sofar)
   struct deppossi *possi, *providelink;
   struct pkginfo *provider, *pkg_pos;
 
-  if (pkg->clientdata->color == black)
+  if (pkg->clientdata->color == PKG_CYCLE_BLACK)
     return false;
-  pkg->clientdata->color = gray;
+  pkg->clientdata->color = PKG_CYCLE_GRAY;
 
   if (debug_has_flag(dbg_depcondetail)) {
     struct varbuf str_pkgs = VARBUF_INIT;
@@ -217,7 +217,7 @@ findbreakcyclerecursive(struct pkginfo *pkg, struct cyclesofarlink *sofar)
     }
   }
   /* Nope, we didn't find a cycle to break. */
-  pkg->clientdata->color = black;
+  pkg->clientdata->color = PKG_CYCLE_BLACK;
   return false;
 }
 
@@ -231,7 +231,7 @@ findbreakcycle(struct pkginfo *pkg)
   iter = pkg_db_iter_new();
   while ((tpkg = pkg_db_iter_next_pkg(iter))) {
     ensure_package_clientdata(tpkg);
-    tpkg->clientdata->color = white;
+    tpkg->clientdata->color = PKG_CYCLE_WHITE;
   }
   pkg_db_iter_free(iter);
 

src/filesdb.c

@@ -103,7 +103,7 @@ ensure_package_clientdata(struct pkginfo *pkg)
     return;
   pkg->clientdata = nfmalloc(sizeof(struct perpackagestate));
   pkg->clientdata->istobe = PKG_ISTOBE_NORMAL;
-  pkg->clientdata->color = white;
+  pkg->clientdata->color = PKG_CYCLE_WHITE;
   pkg->clientdata->fileslistvalid = false;
   pkg->clientdata->files = NULL;
   pkg->clientdata->replacingfilesandsaid = 0;

src/main.h

@@ -38,9 +38,9 @@ enum pkg_istobe {
 };
 
 enum pkg_cycle_color {
-	white,
-	gray,
-	black,
+	PKG_CYCLE_WHITE,
+	PKG_CYCLE_GRAY,
+	PKG_CYCLE_BLACK,
 };
 
 struct perpackagestate {